diff --git a/base64/base64.rs b/base64/base64.rs
index b1898e4d8..7ac2e032a 100644
--- a/base64/base64.rs
+++ b/base64/base64.rs
@@ -97,16 +97,16 @@ fn decode(input: &mut Reader, ignore_garbage: bool) {
         Err(f) => fail!(f.to_str())
     };
 
-    to_decode = str::replace(to_decode, "\n", "");
+    to_decode = str::replace(to_decode.as_slice(), "\n", "");
 
     if ignore_garbage {
         let standard_chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
-        to_decode = to_decode
+        to_decode = to_decode.as_slice()
             .trim_chars(|c| !standard_chars.contains_char(c))
-            .to_owned();
+            .into_owned()
     }
 
-    match to_decode.from_base64() {
+    match to_decode.as_slice().from_base64() {
         Ok(bytes) => {
             let mut out = stdout();
 
@@ -148,7 +148,7 @@ fn encode(input: &mut Reader, line_wrap: uint) {
     // compatibility.
     let final = encoded.replace("\r", "");
 
-    println(final);
+    println(final.as_slice());
 }
 
 fn help(progname: &str, usage: &str) {
diff --git a/basename/basename.rs b/basename/basename.rs
index 58a5a3a15..dd1434097 100644
--- a/basename/basename.rs
+++ b/basename/basename.rs
@@ -24,8 +24,8 @@ static NAME: &'static str = "basename";
 static VERSION: &'static str = "1.0.0";
 
 fn main() {
-    let args: Vec<StrBuf> = os::args().iter().map(|x| x.to_strbuf()).collect();
-    let program = strip_dir(os::args().get(0));
+    let args = os::args();
+    let program = strip_dir(args.get(0).as_slice());
 
     //
     // Argument parsing
@@ -52,20 +52,20 @@ fn main() {
     }
 
     if matches.opt_present("version") {
-        println(program + " " + VERSION);
+        println!("{} {}", program, VERSION);
         return;
     }
 
     // too few arguments
     if args.len() < 2 {
-        println(program + ": missing operand");
-        println("Try `" + program + " --help' for more information.");
+        println!("{}: {}", program, "missing operand");
+        println!("Try '{} --help' for more information.", program);
         return;
     }
     // too many arguments
     else if args.len() > 3 {
-        println(program + ": extra operand `" + args.get(3).as_slice() + "'");
-        println("Try `" + program + " --help' for more information.");
+        println!("{}: extra operand '{}'", program, args.get(3));
+        println!("Try '{} --help' for more information.", program);
         return;
     }
 
@@ -73,19 +73,19 @@ fn main() {
     // Main Program Processing
     //
 
-    let fullname = args.get(1).clone();
+    let fullname = args.get(1);
 
-    let mut name = strip_dir(&fullname.as_slice().to_owned());
+    let mut name = strip_dir(fullname.as_slice());
 
     if args.len() > 2 {
         let suffix = args.get(2).clone();
-        name = strip_suffix(&name, &suffix.to_owned());
+        name = strip_suffix(name.as_slice(), suffix.as_slice());
     }
 
-    println(name);
+    println(name.as_slice());
 }
 
-fn strip_dir(fullname: &~str) -> ~str {
+fn strip_dir(fullname: &str) -> StrBuf {
     let mut name = StrBuf::new();
 
     for c in fullname.chars().rev() {
@@ -98,14 +98,14 @@ fn strip_dir(fullname: &~str) -> ~str {
     return name.as_slice().chars().rev().collect();
 }
 
-fn strip_suffix(name: &~str, suffix: &~str) -> ~str {
+fn strip_suffix(name: &str, suffix: &str) -> StrBuf {
     if name == suffix {
-        return name.clone();
+        return name.into_strbuf();
     }
 
-    if name.ends_with(*suffix) {
-        return name.slice_to(name.len() - suffix.len()).into_owned();
+    if name.ends_with(suffix) {
+        return name.slice_to(name.len() - suffix.len()).into_strbuf();
     }
 
-    return name.clone();
+    return name.into_strbuf();
 }
diff --git a/cat/cat.rs b/cat/cat.rs
index 2ae2d4c36..a86fee6c0 100644
--- a/cat/cat.rs
+++ b/cat/cat.rs
@@ -103,7 +103,7 @@ pub fn exec(files: Vec<StrBuf>, number: NumberingMode, show_nonprint: bool, show
         let is_numbering = number == NumberAll || number == NumberNonEmpty;
 
         for path in files.iter() {
-            let mut reader = match open(path.to_owned()) {
+            let mut reader = match open(path.as_slice()) {
                 Some(f) => f,
                 None => { continue }
             };
@@ -158,7 +158,7 @@ pub fn exec(files: Vec<StrBuf>, number: NumberingMode, show_nonprint: bool, show
     let mut buf = ~[0, .. 1024 * 64];
     // passthru mode
     for path in files.iter() {
-        let mut reader = match open(path.to_owned()) {
+        let mut reader = match open(path.as_slice()) {
             Some(f) => f,
             None => { continue }
         };
@@ -175,7 +175,7 @@ pub fn exec(files: Vec<StrBuf>, number: NumberingMode, show_nonprint: bool, show
     }
 }
 
-fn open(path: ~str) -> Option<Box<Reader>> {
+fn open(path: &str) -> Option<Box<Reader>> {
     if "-" == path {
         return Some(box stdin_raw() as Box<Reader>);
     }
diff --git a/du/du.rs b/du/du.rs
index ea12d1f4e..8f65145f7 100644
--- a/du/du.rs
+++ b/du/du.rs
@@ -32,7 +32,7 @@ static VERSION: &'static str = "1.0.0";
 
 struct Options {
     all: bool,
-    program_name: ~str,
+    program_name: StrBuf,
     max_depth: Option<uint>,
     total: bool,
     separate_dirs: bool,
@@ -268,7 +268,7 @@ ers of 1000).",
         None => 1024
     };
 
-    let convert_size = |size: u64| -> ~str {
+    let convert_size = |size: u64| -> StrBuf {
         if matches.opt_present("human-readable") || matches.opt_present("si") {
             if size > MB {
                 format!("{:.1f}M", (size as f64) / (MB as f64))
diff --git a/echo/echo.rs b/echo/echo.rs
index 6486fbf36..c1979d61d 100644
--- a/echo/echo.rs
+++ b/echo/echo.rs
@@ -118,7 +118,7 @@ fn main() {
         let string = matches.free.connect(" ");
         if matches.opt_present("e") {
             let mut prev_was_slash = false;
-            let mut iter = string.chars().enumerate();
+            let mut iter = string.as_slice().chars().enumerate();
             loop {
                 match iter.next() {
                     Some((index, c)) => {
@@ -142,7 +142,7 @@ fn main() {
                                 't' => print_char('\t'),
                                 'v' => print_char('\x0B'),
                                 'x' => {
-                                    let (c, num_char_used) = convert_str(string, index + 1, 16u);
+                                    let (c, num_char_used) = convert_str(string.as_slice(), index + 1, 16u);
                                     if num_char_used == 0 {
                                         print_char('\\');
                                         print_char('x');
@@ -154,7 +154,7 @@ fn main() {
                                     }
                                 },
                                 '0' => {
-                                    let (c, num_char_used) = convert_str(string, index + 1, 8u);
+                                    let (c, num_char_used) = convert_str(string.as_slice(), index + 1, 8u);
                                     if num_char_used == 0 {
                                         print_char('\\');
                                         print_char('0');
@@ -176,7 +176,7 @@ fn main() {
                 }
             }
         } else {
-            print(string);
+            print(string.as_slice());
         }
     }
 
diff --git a/env/env.rs b/env/env.rs
index 15f0c1e98..ed7afb63b 100644
--- a/env/env.rs
+++ b/env/env.rs
@@ -16,9 +16,9 @@
 struct options {
     ignore_env: bool,
     null: bool,
-    unsets: Vec<~str>,
-    sets: Vec<(~str, ~str)>,
-    program: Vec<~str>
+    unsets: Vec<StrBuf>,
+    sets: Vec<(StrBuf, StrBuf)>,
+    program: Vec<StrBuf>
 }
 
 fn usage(prog: &str) {
@@ -77,7 +77,7 @@ fn main() {
 
         if wait_cmd {
             // we still accept NAME=VAL here but not other options
-            let mut sp = opt.splitn('=', 1);
+            let mut sp = opt.as_slice().splitn('=', 1);
             let name = sp.next();
             let value = sp.next();
 
@@ -91,7 +91,7 @@ fn main() {
                     break;
                 }
             }
-        } else if opt.starts_with("--") {
+        } else if opt.as_slice().starts_with("--") {
             match opt.as_slice() {
                 "--help" => { usage(prog); return }
                 "--version" => { version(); return }
@@ -113,7 +113,7 @@ fn main() {
                     return
                 }
             }
-        } else if opt.starts_with("-") {
+        } else if opt.as_slice().starts_with("-") {
             if opt.len() == 0 {
                 // implies -i and stop parsing opts
                 wait_cmd = true;
@@ -121,7 +121,7 @@ fn main() {
                 continue;
             }
 
-            let mut chars = opt.chars();
+            let mut chars = opt.as_slice().chars();
             chars.next();
 
             for c in chars {
@@ -148,7 +148,7 @@ fn main() {
             }
         } else {
             // is it a NAME=VALUE like opt ?
-            let mut sp = opt.splitn('=', 1);
+            let mut sp = opt.as_slice().splitn('=', 1);
             let name = sp.next();
             let value = sp.next();
 
diff --git a/fold/fold.rs b/fold/fold.rs
index 9f40063ea..483d212e4 100644
--- a/fold/fold.rs
+++ b/fold/fold.rs
@@ -82,24 +82,24 @@ fn main() {
     }
 }
 
-fn handle_obsolete(args: ~[~str]) -> (~[~str], Option<~str>) {
-    let mut args: Vec<~str> = args.move_iter().collect();
+fn handle_obsolete(args: &[StrBuf]) -> (Vec<StrBuf>, Option<StrBuf>) {
+    let mut args = Vec::<StrBuf>::from_slice(args);
     let mut i = 0;
     while i < args.len() {
-        if args.get(i).char_at(0) == '-' && args.get(i).len() > 1 && args.get(i).char_at(1).is_digit() {
-            return (args.as_slice().to_owned(),
-                    Some(args.remove(i).unwrap().slice_from(1).to_owned()));
+        if args.get(i).as_slice().char_at(0) == '-' && args.get(i).len() > 1 && args.get(i).as_slice().char_at(1).is_digit() {
+            return (args.clone(),
+                    Some(args.remove(i).unwrap().as_slice().slice_from(1).to_owned()));
         }
         i += 1;
     }
-    (args.as_slice().to_owned(), None)
+    (args, None)
 }
 
 fn fold(filenames: Vec<StrBuf>, bytes: bool, spaces: bool, width: uint) {
     for filename in filenames.iter() {
         let filename: &str = filename.as_slice();
         let buffer = BufferedReader::new(
-            if filename == "-".to_owned() {
+            if filename == "-" {
                 box io::stdio::stdin_raw() as Box<Reader>
             } else {
                 box safe_unwrap!(File::open(&Path::new(filename))) as Box<Reader>
@@ -117,7 +117,7 @@ fn fold_file<T: io::Reader>(file: BufferedReader<T>, bytes: bool, spaces: bool,
             println!("");
             continue;
         }
-        let line = line.slice_to(line.len() - 1);
+        let line = line.as_slice().slice_to(line.len() - 1);
         if bytes {
             let mut i = 0;
             while i < line.len() {
@@ -173,7 +173,7 @@ fn fold_file<T: io::Reader>(file: BufferedReader<T>, bytes: bool, spaces: bool,
                                 match slice.rfind(|ch: char| ch.is_whitespace()) {
                                     Some(m) => {
                                         let routput = slice.slice_from(m + 1).to_owned();
-                                        let ncount = routput.chars().fold(0, |out, ch: char| out + if ch == '\t' { 8 } else { 1 });
+                                        let ncount = routput.as_slice().chars().fold(0, |out, ch: char| out + if ch == '\t' { 8 } else { 1 });
                                         (slice.slice_to(m + 1), routput, ncount)
                                     },
                                     None => (slice, "".to_owned(), 0)
diff --git a/head/head.rs b/head/head.rs
index 27fd08911..8b6ed08f4 100644
--- a/head/head.rs
+++ b/head/head.rs
@@ -26,7 +26,7 @@ fn main () {
     let mut line_count = 10u;
 
     // handle obsolete -number syntax
-    let options = match obsolete(os::args().tail().to_owned()) {
+    let options = match obsolete(os::args().tail()) {
         (args, Some(n)) => { line_count = n; args },
         (args, None) => args
     };
@@ -96,14 +96,14 @@ fn main () {
 //
 // In case is found, the options vector will get rid of that object so that
 // getopts works correctly.
-fn obsolete (options: ~[~str]) -> (~[~str], Option<uint>) {
-    let mut options: Vec<~str> = options.move_iter().collect();
+fn obsolete (options: &[StrBuf]) -> (Vec<StrBuf>, Option<uint>) {
+    let mut options: Vec<StrBuf> = Vec::from_slice(options);
     let mut a = 0;
     let b = options.len();
-    let mut current;
 
     while a < b {
-        current = options.get(a).clone();
+        let current = options.get(a).clone();
+        let current = current.as_slice();
 
         if current.len() > 1 && current[0] == '-' as u8 {
             let len = current.len();
@@ -115,7 +115,7 @@ fn obsolete (options: ~[~str]) -> (~[~str], Option<uint>) {
                 if pos == len - 1 {
                     options.remove(a);
                     let number : Option<uint> = from_str(current.slice(1,len));
-                    return (options.as_slice().to_owned(), Some(number.unwrap()));
+                    return (options, Some(number.unwrap()));
                 }
             }
         }
@@ -123,7 +123,7 @@ fn obsolete (options: ~[~str]) -> (~[~str], Option<uint>) {
         a += 1;
     };
 
-    (options.as_slice().to_owned(), None)
+    (options, None)
 }
 
 fn head<T: Reader> (reader: &mut BufferedReader<T>, line_count:uint) {
diff --git a/hostid/hostid.rs b/hostid/hostid.rs
index f616ef622..4951940ab 100644
--- a/hostid/hostid.rs
+++ b/hostid/hostid.rs
@@ -52,7 +52,7 @@ extern {
 fn main() {
     let args: Vec<StrBuf> = os::args().iter().map(|x| x.to_strbuf()).collect();
 
-    let opts = ~[
+    let opts = [
         optflag("", "help", "display this help and exit"),
         optflag("", "version", "output version information and exit"),
     ];
@@ -87,9 +87,8 @@ fn version() {
     println!("{} {}", NAME, VERSION);
 }
 
-fn get_help_text(progname: &str, usage: &str) -> ~str {
-    let msg = format!("Usage: \n {0} {1}", progname, usage);
-    msg
+fn get_help_text(progname: &str, usage: &str) -> StrBuf {
+    format!("Usage: \n {0} {1}", progname, usage)
 }
 
 fn help(progname: &str, usage: &str) {
diff --git a/hostname/hostname.rs b/hostname/hostname.rs
index 3292e4a2b..9155d7b5d 100644
--- a/hostname/hostname.rs
+++ b/hostname/hostname.rs
@@ -36,31 +36,31 @@ fn main () {
 
     let matches = match getopts(args.tail(), options) {
         Ok(m) => { m }
-        _ => { help_menu(program, options); return; }
+        _ => { help_menu(program.as_slice(), options); return; }
     };
 
     if matches.opt_present("h") {
-        help_menu(program, options);
+        help_menu(program.as_slice(), options);
         return
     }
     if matches.opt_present("V") { version(); return }
 
     match matches.free.len() {
         0 => {
-            let hostname: ~str = xgethostname();
+            let hostname = xgethostname();
 
             if matches.opt_present("s") {
-                let pos = hostname.find_str(".");
+                let pos = hostname.as_slice().find_str(".");
                 if pos.is_some() {
-                    println!("{:s}", hostname.slice_to(pos.unwrap()));
+                    println!("{:s}", hostname.as_slice().slice_to(pos.unwrap()));
                     return;
                 }
             }
 
-            println!("{:s}", hostname);
+            println!("{:s}", hostname.as_slice());
         }
-        1 => { xsethostname( &matches.free.last().unwrap().as_slice().to_owned() ) }
-        _ => { help_menu(program, options); }
+        1 => { xsethostname( matches.free.last().unwrap().as_slice() ) }
+        _ => { help_menu(program.as_slice(), options); }
     };
 }
 
@@ -77,7 +77,7 @@ fn help_menu(program: &str, options: &[getopts::OptGroup]) {
     print!("{:s}", usage("Print or set the system's host name.", options));
 }
 
-fn xgethostname() -> ~str {
+fn xgethostname() -> StrBuf {
     let namelen = 256u;
     let mut name = Vec::from_elem(namelen, 0u8);
 
@@ -95,7 +95,7 @@ fn xgethostname() -> ~str {
     str::from_utf8(name.slice_to(last_char)).unwrap().to_owned()
 }
 
-fn xsethostname(name: &~str) {
+fn xsethostname(name: &str) {
     let vec_name: Vec<libc::c_char> = name.bytes().map(|c| c as i8).collect();
 
     let err = unsafe {
@@ -103,6 +103,6 @@ fn xsethostname(name: &~str) {
     };
 
     if err != 0 {
-        println!("Cannot set hostname to {:s}", *name);
+        println!("Cannot set hostname to {:s}", name);
     }
 }
diff --git a/kill/kill.rs b/kill/kill.rs
index 076f61edc..97e2e681a 100644
--- a/kill/kill.rs
+++ b/kill/kill.rs
@@ -121,12 +121,12 @@ fn table() {
     }
 }
 
-fn print_signal(signal_name_or_value: ~str) {
+fn print_signal(signal_name_or_value: &str) {
     for signal in ALL_SIGNALS.iter() {
-        if signal.name == signal_name_or_value  || ("SIG" + signal.name) == signal_name_or_value {
+        if signal.name == signal_name_or_value  || (format!("SIG{}", signal.name).as_slice()) == signal_name_or_value {
             println!("{}", signal.value)
             exit!(EXIT_OK)
-        } else if signal_name_or_value == signal.value.to_str() {
+        } else if signal_name_or_value == signal.value.to_str().as_slice() {
             println!("{}", signal.name);
             exit!(EXIT_OK)
         }
@@ -151,27 +151,26 @@ fn print_signals() {
 
 fn list(arg: Option<StrBuf>) {
     match arg {
-      Some(x) => print_signal(x.to_owned()),
+      Some(x) => print_signal(x.as_slice()),
       None => print_signals(),
     };
 }
 
-fn get_help_text(progname: &str, usage: &str) -> ~str {
-    let msg = format!("Usage: \n {0} {1}", progname, usage);
-    msg
+fn get_help_text(progname: &str, usage: &str) -> StrBuf {
+    format!("Usage: \n {0} {1}", progname, usage)
 }
 
 fn help(progname: &str, usage: &str) {
     println!("{}", get_help_text(progname, usage));
 }
 
-fn signal_by_name_or_value(signal_name_or_value:~str) -> Option<uint> {
-    if signal_name_or_value == "0".to_owned() {
+fn signal_by_name_or_value(signal_name_or_value: &str) -> Option<uint> {
+    if signal_name_or_value == "0" {
         return Some(0);
     }
     for signal in ALL_SIGNALS.iter() {
-        let long_name = "SIG" + signal.name;
-        if signal.name == signal_name_or_value  || (signal_name_or_value == signal.value.to_str()) || (long_name == signal_name_or_value) {
+        let long_name = format!("SIG{}", signal.name);
+        if signal.name == signal_name_or_value  || (signal_name_or_value == signal.value.to_str().as_slice()) || (long_name.as_slice() == signal_name_or_value) {
             return Some(signal.value);
         }
     }
@@ -179,7 +178,7 @@ fn signal_by_name_or_value(signal_name_or_value:~str) -> Option<uint> {
 }
 
 fn kill(signalname: &str, pids: std::vec::Vec<StrBuf>) {
-    let optional_signal_value = signal_by_name_or_value(signalname.to_owned());
+    let optional_signal_value = signal_by_name_or_value(signalname);
     let signal_value = match optional_signal_value {
         Some(x) => x,
         None => crash!(EXIT_ERR, "unknown signal name {}", signalname)
diff --git a/logname/logname.rs b/logname/logname.rs
index 8bbf7a908..72aff7554 100644
--- a/logname/logname.rs
+++ b/logname/logname.rs
@@ -18,7 +18,7 @@
 extern crate getopts;
 extern crate libc;
 
-use std::io::{print, println};
+use std::io::print;
 use std::os;
 use std::str;
 use libc::c_char;
@@ -30,7 +30,7 @@ extern {
     pub fn getlogin() -> *libc::c_char;
 }
 
-unsafe fn get_userlogin() -> ~str {
+unsafe fn get_userlogin() -> StrBuf {
     let login: *libc::c_char = getlogin();
 
     str::raw::from_c_str(login)
@@ -40,7 +40,7 @@ static NAME: &'static str = "logname";
 static VERSION: &'static str = "1.0.0";
 
 fn version() {
-    println(NAME + " " + VERSION);
+    println!("{} {}", NAME, VERSION);
 }
 
 fn main() {
diff --git a/md5sum/md5sum.rs b/md5sum/md5sum.rs
index fce9218da..ba4305979 100644
--- a/md5sum/md5sum.rs
+++ b/md5sum/md5sum.rs
@@ -84,7 +84,7 @@ fn md5sum(files: Vec<StrBuf>, binary: bool, check: bool, tag: bool, status: bool
     for filename in files.iter() {
         let filename: &str = filename.as_slice();
         let mut file = BufferedReader::new(
-            if filename == "-".to_owned() {
+            if filename == "-" {
                 box stdin_raw() as Box<Reader>
             } else {
                 box safe_unwrap!(File::open(&Path::new(filename))) as Box<Reader>
@@ -95,9 +95,9 @@ fn md5sum(files: Vec<StrBuf>, binary: bool, check: bool, tag: bool, status: bool
             //let mut buffer = BufferedReader::new(file);
             for (i, line) in buffer.lines().enumerate() {
                 let line = safe_unwrap!(line);
-                let (ck_filename, sum) = match from_gnu(line, bytes) {
+                let (ck_filename, sum) = match from_gnu(line.as_slice(), bytes) {
                     Some(m) => m,
-                    None => match from_bsd(line, bytes) {
+                    None => match from_bsd(line.as_slice(), bytes) {
                         Some(m) => m,
                         None => {
                             bad_format += 1;
@@ -112,7 +112,7 @@ fn md5sum(files: Vec<StrBuf>, binary: bool, check: bool, tag: bool, status: bool
                     }
                 };
                 let real_sum = calc_sum(&mut md5, &mut safe_unwrap!(File::open(&Path::new(ck_filename))), binary);
-                if sum == real_sum {
+                if sum == real_sum.as_slice() {
                     if !quiet {
                         println!("{}: OK", ck_filename);
                     }
@@ -145,15 +145,15 @@ fn md5sum(files: Vec<StrBuf>, binary: bool, check: bool, tag: bool, status: bool
     }
 }
 
-fn calc_sum(md5: &mut crypto::md5::Md5, file: &mut Reader, binary: bool) -> ~str {
+fn calc_sum(md5: &mut crypto::md5::Md5, file: &mut Reader, binary: bool) -> StrBuf {
     let data =
         if binary {
-            (safe_unwrap!(file.read_to_end())).as_slice().to_owned()
+            (safe_unwrap!(file.read_to_end()))
         } else {
             (safe_unwrap!(file.read_to_str())).into_bytes()
         };
     md5.reset();
-    md5.input(data);
+    md5.input(data.as_slice());
     md5.result_str()
 }
 
diff --git a/mkdir/mkdir.rs b/mkdir/mkdir.rs
index 4d4084bcf..6755b02fd 100644
--- a/mkdir/mkdir.rs
+++ b/mkdir/mkdir.rs
@@ -89,8 +89,7 @@ fn print_help(opts: &[getopts::OptGroup]) {
     println!("mkdir v{} - make a new directory with the given path", VERSION);
     println!("");
     println!("Usage:");
-    print!("{}", getopts::usage("Create the given DIRECTORY(ies)" +
-                               " if they do not exist", opts));
+    print!("{}", getopts::usage("Create the given DIRECTORY(ies) if they do not exist", opts));
 }
 
 /**
diff --git a/paste/paste.rs b/paste/paste.rs
index e20aea39f..0a33fe5c7 100644
--- a/paste/paste.rs
+++ b/paste/paste.rs
@@ -66,23 +66,26 @@ fn paste(filenames: Vec<StrBuf>, serial: bool, delimiters: &str) {
             }
         )
     ).collect();
-    let delimiters: Vec<~str> = delimiters.chars().map(|x| x.to_str()).collect();
+    let delimiters: Vec<StrBuf> = delimiters.chars().map(|x| x.to_str()).collect();
     let mut delim_count = 0;
     if serial {
         for file in files.mut_iter() {
-            let mut output = "".to_owned();
+            let mut output = StrBuf::new();
             loop {
-                output = output + match file.read_line() {
-                    Ok(line) => line.trim_right() + delimiters.get(delim_count % delimiters.len()).clone(),
+                match file.read_line() {
+                    Ok(line) => {
+                        output.push_str(line.as_slice().trim_right());
+                        output.push_str(delimiters.get(delim_count % delimiters.len()).as_slice());
+                    }
                     Err(f) => if f.kind == io::EndOfFile {
                         break
                     } else {
                         crash!(1, "{}", f.to_str())
                     }
-                };
+                }
                 delim_count += 1;
             }
-            println!("{}", output.slice_to(output.len() - 1));
+            println!("{}", output.as_slice().slice_to(output.len() - 1));
         }
     } else {
         let mut eof = Vec::from_elem(files.len(), false);
@@ -94,7 +97,7 @@ fn paste(filenames: Vec<StrBuf>, serial: bool, delimiters: &str) {
                     eof_count += 1;
                 } else {
                     match file.read_line() {
-                        Ok(line) => output = output + line.slice_to(line.len() - 1),
+                        Ok(line) => output.push_str(line.as_slice().slice_to(line.len() - 1)),
                         Err(f) => if f.kind == io::EndOfFile {
                             *eof.get_mut(i) = true;
                             eof_count += 1;
@@ -103,13 +106,13 @@ fn paste(filenames: Vec<StrBuf>, serial: bool, delimiters: &str) {
                         }
                     }
                 }
-                output = output + delimiters.get(delim_count % delimiters.len()).clone();
+                output.push_str(delimiters.get(delim_count % delimiters.len()).as_slice());
                 delim_count += 1;
             }
             if files.len() == eof_count {
                 break;
             }
-            println!("{}", output.slice_to(output.len() - 1));
+            println!("{}", output.as_slice().slice_to(output.len() - 1));
             delim_count = 0;
         }
     }
diff --git a/printenv/printenv.rs b/printenv/printenv.rs
index 92a4770ae..fe3871827 100644
--- a/printenv/printenv.rs
+++ b/printenv/printenv.rs
@@ -72,7 +72,7 @@ pub fn exec(args: Vec<StrBuf>, separator: &str) {
     for env_var in args.iter() {
         match os::getenv(env_var.as_slice()) {
             Some(var) => {
-                print(var);
+                print(var.as_slice());
                 print(separator);
             }
             _ => ()
diff --git a/rm/rm.rs b/rm/rm.rs
index 1d7286efa..468eb2127 100644
--- a/rm/rm.rs
+++ b/rm/rm.rs
@@ -192,9 +192,9 @@ fn remove_file(path: &Path, name: &str, interactive: InteractiveMode, verbose: b
 
 fn prompt_file(path: &Path, name: &str) -> bool {
     if path.is_dir() {
-        prompt(format!("Remove directory '{}'? ", name))
+        prompt(format!("Remove directory '{}'? ", name).as_slice())
     } else {
-        prompt(format!("Remove file '{}'? ", name))
+        prompt(format!("Remove file '{}'? ", name).as_slice())
     }
 }
 
@@ -207,7 +207,7 @@ fn read_prompt() -> bool {
     stdio::flush();
     match BufferedReader::new(stdin()).read_line() {
         Ok(line) => {
-            match line.char_at(0) {
+            match line.as_slice().char_at(0) {
                 'y' | 'Y' => true,
                 'n' | 'N' => false,
                 _ => {
diff --git a/seq/seq.rs b/seq/seq.rs
index cf7918bea..e73efd8b3 100644
--- a/seq/seq.rs
+++ b/seq/seq.rs
@@ -21,14 +21,14 @@ fn print_usage(opts: ~[getopts::OptGroup]) {
     println!("{:s}", getopts::usage("Print sequences of numbers", opts));
 }
 
-fn parse_float(s: &str) -> Result<f32, ~str>{
+fn parse_float(s: &str) -> Result<f32, StrBuf>{
     match from_str(s) {
         Some(n) => Ok(n),
         None => Err(format!("seq: invalid floating point argument: {:s}", s))
     }
 }
 
-fn escape_sequences(s: &str) -> ~str {
+fn escape_sequences(s: &str) -> StrBuf {
     s.replace("\\n", "\n").
         replace("\\t", "\t")
 }
@@ -96,7 +96,7 @@ fn done_printing(next: f32, step: f32, last: f32) -> bool {
     }
 }
 
-fn print_seq(first: f32, step: f32, last: f32, separator: ~str, terminator: ~str, pad: bool) {
+fn print_seq(first: f32, step: f32, last: f32, separator: StrBuf, terminator: StrBuf, pad: bool) {
     let mut i = first;
     let maxlen = first.max(last).to_str().len();
     while !done_printing(i, step, last) {
diff --git a/sleep/sleep.rs b/sleep/sleep.rs
index 27e26c80a..f85ab8faf 100644
--- a/sleep/sleep.rs
+++ b/sleep/sleep.rs
@@ -67,17 +67,17 @@ fn sleep(args: Vec<StrBuf>) {
         let (arg, suffix_time) = match match_suffix(arg.as_slice()) {
             Ok(m) => m,
             Err(f) => {
-                crash!(1, "{}", f)
+                crash!(1, "{}", f.to_strbuf())
             }
         };
         let num =
             if suffix_time == 0 {
                 0.0
             } else {
-                match num::from_str_radix::<f64>((arg), 10) {
+                match num::from_str_radix::<f64>((arg.as_slice()), 10) {
                     Some(m) => m,
                     None => {
-                        crash!(1, "Invalid time interval '{}'", arg)
+                        crash!(1, "Invalid time interval '{}'", arg.to_strbuf())
                     }
                 }
             };
@@ -86,7 +86,7 @@ fn sleep(args: Vec<StrBuf>) {
     timer::sleep((sleep_time * 1000.0) as u64);
 }
 
-fn match_suffix(arg: &str) -> Result<(~str, int), ~str> {
+fn match_suffix(arg: &str) -> Result<(StrBuf, int), StrBuf> {
     let result = match (arg).char_at_reverse(0) {
         's' | 'S' => 1,
         'm' | 'M' => 60,
@@ -94,7 +94,7 @@ fn match_suffix(arg: &str) -> Result<(~str, int), ~str> {
         'd' | 'D' => 60 * 60 * 24,
         val => {
             if !val.is_alphabetic() {
-                return Ok(((arg).to_owned(), 1))
+                return Ok((arg.to_strbuf(), 1))
             } else {
                 return Err(format!("Invalid time interval '{}'", arg))
             }
diff --git a/tac/tac.rs b/tac/tac.rs
index 2e6dacc76..c2642a354 100644
--- a/tac/tac.rs
+++ b/tac/tac.rs
@@ -79,21 +79,24 @@ fn tac(filenames: Vec<StrBuf>, before: bool, _: bool, separator: &str) {
             }
         );
         let mut data = crash_if_err!(1, file.read_to_str());
-        if data.ends_with("\n") {
+        if data.as_slice().ends_with("\n") {
             // removes blank line that is inserted otherwise
             let mut buf = data.into_strbuf();
             let len = buf.len();
             buf.truncate(len - 1);
             data = buf.into_owned();
         }
-        let split_vec: Vec<&str> = data.split_str(separator).collect();
-        let rev: ~str = split_vec.iter().rev().fold("".to_owned(), |a, &b|
-            a + if before {
-                separator + b
+        let split_vec: Vec<&str> = data.as_slice().split_str(separator).collect();
+        let rev: StrBuf = split_vec.iter().rev().fold(StrBuf::new(), |mut a, &b| {
+            if before {
+               a.push_str(separator);
+               a.push_str(b);
             } else {
-                b + separator
+                a.push_str(b);
+                a.push_str(separator);
             }
-        );
+            a
+        });
         print!("{}", rev);
     }
 }
diff --git a/tee/tee.rs b/tee/tee.rs
index 731fbe26b..08174dc2a 100644
--- a/tee/tee.rs
+++ b/tee/tee.rs
@@ -32,14 +32,14 @@ fn main() {
 }
 
 struct Options {
-    program: ~str,
+    program: StrBuf,
     append: bool,
     ignore_interrupts: bool,
-    print_and_exit: Option<~str>,
+    print_and_exit: Option<StrBuf>,
     files: Box<Vec<Path>>
 }
 
-fn options(args: &[~str]) -> Result<Options, ()> {
+fn options(args: &[StrBuf]) -> Result<Options, ()> {
     let opts = ~[
         optflag("a", "append", "append to the given FILEs, do not overwrite"),
         optflag("i", "ignore-interrupts", "ignore interrupt signals"),
@@ -53,8 +53,7 @@ fn options(args: &[~str]) -> Result<Options, ()> {
         let version = format!("{} {}", NAME, VERSION);
         let program = args.get(0).as_slice();
         let arguments = "[OPTION]... [FILE]...";
-        let brief = "Copy standard input to each FILE, and also to standard " +
-                    "output.";
+        let brief = "Copy standard input to each FILE, and also to standard output.";
         let comment = "If a FILE is -, copy again to standard output.";
         let help = format!("{}\n\nUsage:\n  {} {}\n\n{}\n{}",
                            version, program, arguments, usage(brief, opts),
@@ -64,7 +63,7 @@ fn options(args: &[~str]) -> Result<Options, ()> {
                        else if m.opt_present("version") { Some(version) }
                        else { None };
         Ok(Options {
-            program: program.into_owned(),
+            program: program.to_strbuf(),
             append: m.opt_present("append"),
             ignore_interrupts: m.opt_present("ignore-interrupts"),
             print_and_exit: to_print,
@@ -75,7 +74,7 @@ fn options(args: &[~str]) -> Result<Options, ()> {
 
 fn exec(options: Options) -> Result<(), ()> {
     match options.print_and_exit {
-        Some(text) => Ok(println(text)),
+        Some(text) => Ok(println(text.as_slice())),
         None => tee(options)
     }
 }
@@ -145,7 +144,7 @@ impl Reader for NamedReader {
 
 fn with_path<T>(path: &Path, cb: || -> IoResult<T>) -> IoResult<T> {
     match cb() {
-        Err(f) => { warn(format!("{}: {}", path.display(), f.to_str())); Err(f) }
+        Err(f) => { warn(format!("{}: {}", path.display(), f.to_str()).as_slice()); Err(f) }
         okay => okay
     }
 }
diff --git a/truncate/truncate.rs b/truncate/truncate.rs
index 039af2fb8..26b9f449c 100644
--- a/truncate/truncate.rs
+++ b/truncate/truncate.rs
@@ -178,7 +178,7 @@ fn parse_size(size: &str) -> (u64, TruncateMode) {
         }
         slice
     }.to_owned().into_bytes();
-    let mut number = match u64::parse_bytes(bytes, 10) {
+    let mut number = match u64::parse_bytes(bytes.as_slice(), 10) {
         Some(num) => num,
         None => {
             crash!(1, "'{}' is not a valid number.", size)
diff --git a/tty/tty.rs b/tty/tty.rs
index cd482fae1..a5502c101 100644
--- a/tty/tty.rs
+++ b/tty/tty.rs
@@ -55,8 +55,8 @@ fn main () {
     let tty = unsafe { str::raw::from_c_str(ttyname(libc::STDIN_FILENO)) };
 
     if !silent {
-        if !tty.is_whitespace() {
-            println(tty);
+        if !tty.as_slice().is_whitespace() {
+            println(tty.as_slice());
         } else {
             println!("not a tty");
         }
diff --git a/uname/uname.rs b/uname/uname.rs
index 2b2fce57c..b9d90ac19 100644
--- a/uname/uname.rs
+++ b/uname/uname.rs
@@ -27,11 +27,11 @@ use c_types::utsname;
 #[path = "../common/c_types.rs"] mod c_types;
 
 struct utsrust {
-    sysname: ~str,
-    nodename: ~str,
-    release: ~str,
-    version: ~str,
-    machine: ~str
+    sysname: StrBuf,
+    nodename: StrBuf,
+    release: StrBuf,
+    version: StrBuf,
+    machine: StrBuf 
 }
 
 extern {
@@ -81,24 +81,24 @@ fn main() {
     let mut output = StrBuf::new();
     if matches.opt_present("sysname") || matches.opt_present("all")
         || !matches.opts_present(["nodename".to_strbuf(), "release".to_strbuf(), "version".to_strbuf(), "machine".to_strbuf()]) {
-            output.push_str(uname.sysname);
+            output.push_str(uname.sysname.as_slice());
             output.push_str(" ");
     }
 
     if matches.opt_present("nodename") || matches.opt_present("all") {
-        output.push_str(uname.nodename);
+        output.push_str(uname.nodename.as_slice());
         output.push_str(" ");
     }
     if matches.opt_present("release") || matches.opt_present("all") {
-        output.push_str(uname.release);
+        output.push_str(uname.release.as_slice());
         output.push_str(" ");
     }
     if matches.opt_present("version") || matches.opt_present("all") {
-        output.push_str(uname.version);
+        output.push_str(uname.version.as_slice());
         output.push_str(" ");
     }
     if matches.opt_present("machine") || matches.opt_present("all") {
-        output.push_str(uname.machine);
+        output.push_str(uname.machine.as_slice());
         output.push_str(" ");
     }
     println!("{}", output.as_slice().trim_left())
diff --git a/uptime/uptime.rs b/uptime/uptime.rs
index 21e5c4dbb..12650d24d 100644
--- a/uptime/uptime.rs
+++ b/uptime/uptime.rs
@@ -167,8 +167,8 @@ fn get_uptime(boot_time: Option<time_t>) -> i64 {
              }
     };
 
-    match uptime_text.words().next() {
-        Some(s) => match from_str(s.replace(".","")) {
+    match uptime_text.as_slice().words().next() {
+        Some(s) => match from_str(s.replace(".","").as_slice()) {
                     Some(n) => n,
                     None => -1
                    },
diff --git a/wc/wc.rs b/wc/wc.rs
index ec3fb5598..53be97909 100644
--- a/wc/wc.rs
+++ b/wc/wc.rs
@@ -23,7 +23,7 @@ use getopts::Matches;
 mod util;
 
 struct Result {
-    filename: ~str,
+    filename: StrBuf,
     bytes: uint,
     chars: uint,
     lines: uint,
@@ -155,7 +155,7 @@ pub fn wc(files: Vec<StrBuf>, matches: &Matches) {
         }
 
         results.push(Result {
-            filename: path.as_slice().to_owned(),
+            filename: path.to_strbuf(),
             bytes: byte_count,
             chars: char_count,
             lines: line_count,
@@ -177,15 +177,15 @@ pub fn wc(files: Vec<StrBuf>, matches: &Matches) {
     }
 
     for result in results.iter() {
-        print_stats(&result.filename, result.lines, result.words, result.chars, result.bytes, result.max_line_length, matches, max_str_len);
+        print_stats(result.filename.as_slice(), result.lines, result.words, result.chars, result.bytes, result.max_line_length, matches, max_str_len);
     }
 
     if files.len() > 1 {
-        print_stats(&"total".to_owned(), total_line_count, total_word_count, total_char_count, total_byte_count, total_longest_line_length, matches, max_str_len);
+        print_stats("total", total_line_count, total_word_count, total_char_count, total_byte_count, total_longest_line_length, matches, max_str_len);
     }
 }
 
-fn print_stats(filename: &~str, line_count: uint, word_count: uint, char_count: uint,
+fn print_stats(filename: &str, line_count: uint, word_count: uint, char_count: uint,
     byte_count: uint, longest_line_length: uint, matches: &Matches, max_str_len: uint) {
     if matches.opt_present("lines") {
         print!("{:1$}", line_count, max_str_len);
@@ -214,16 +214,16 @@ fn print_stats(filename: &~str, line_count: uint, word_count: uint, char_count:
         print!("{:1$}", byte_count, max_str_len + 1);
     }
 
-    if *filename != "-".to_owned() {
-        println!(" {}", *filename);
+    if filename != "-" {
+        println!(" {}", filename.as_slice());
     }
     else {
         println!("");
     }
 }
 
-fn open(path: ~str) -> Option<BufferedReader<Box<Reader>>> {
-    if "-" == path {
+fn open(path: StrBuf) -> Option<BufferedReader<Box<Reader>>> {
+    if "-" == path.as_slice() {
         let reader = box stdin() as Box<Reader>;
         return Some(BufferedReader::new(reader));
     }
diff --git a/whoami/whoami.rs b/whoami/whoami.rs
index 20794e78d..56e04b3b8 100644
--- a/whoami/whoami.rs
+++ b/whoami/whoami.rs
@@ -30,7 +30,7 @@ extern {
     pub fn geteuid() -> libc::c_int;
 }
 
-unsafe fn getusername() -> ~str {
+unsafe fn getusername() -> StrBuf {
     let passwd: *c_passwd = getpwuid(geteuid());
 
     let pw_name: *libc::c_char = (*passwd).pw_name;
diff --git a/yes/yes.rs b/yes/yes.rs
index e88aec95a..004be59f0 100644
--- a/yes/yes.rs
+++ b/yes/yes.rs
@@ -55,10 +55,10 @@ fn main() {
         string = matches.free.connect(" ");
     }
 
-    exec(string);
+    exec(string.as_slice());
 }
 
-pub fn exec(string: ~str) {
+pub fn exec(string: &str) {
     loop {
         println(string);
     }