MarMOTS is a real-time multiplayer ASCII whiteboard playable using any Flash-enabled internet browser, in which participants can pretty much write or draw whatever they want inside the same room. Pictures are saved to the gallery occasionally, allowing anyone to browse through any awesome art contributions made in the past.

Note that pressing the Tab or Enter key will cause problems, so use the delete and space key to access the menu and confirm a selection instead. Chat room support is currently in the works. (source)