Check out this game, it's awesome:
http://ps3.ign.com/objects/856/856680.html The graphics are incredible, and it looks really fun. Basically, all 4 players connect online and have to work together to solve puzzles. Also I guess their is a pretty in depth level editor where multiple people can work on a level at the same time. Don't know if it's worth the 700 price of admission, but still pretty awesome none the less.