Pastebin.com - Pastebin.com is a website where you can store text for a certain period of time.
codebunk - Realtime Collaborative Editor with Code Execution, REPLs and Chat
GitHub Gist - Gist is a simple way to share snippets and pastes with others.
Floobits - Floobits brings real-time collaborative editing to text editors, IDEs, and now Atom.
hastebin - Pad editor for source code.
coderpad - Collaborative code editor with in-browser, real-time execution. Conduct programming phone screens like a boss.