http://vimeo.com/15978113 My buddy just released a cool collaborative drawing tool that's worth looking at. Think of it as Your World of Text for images. It's called The Grid and the best of the drawings are posted here on Posterous. There is some seriously creative work; it is mostly 8-bit video game themed for obvious reasons, but it is cool nonetheless.
Check it out: http://claytron.org/grid/grid.html