codepad.org is an online compiler/interpreter, and a simple collaboration tool. It’s a pastebin that executes code for you. You paste your code, and codepad runs it and gives you a short URL you can use to share it.
What I like most, is how simple it is to use. Check out the Python example I created. Don’t worry if Python isn’t you bag, it also supports Ruby, Perl, Haskell, PHP, C and more.