"Glitch is a web-based massively-multiplayer game which takes place inside the minds of eleven peculiarly imaginative Giants. You choose how to grow and shape the world: building and developing, learning new skills, collaborating or competing with everyone else in one enormous, ever-changing, persistent world."
MMO's have so much to offer in terms of collaboration, communication, and system-thinking. They tend to be very compelling, however, so be sure to set firm boundaries for game-play. Glitch is still in Beta. I've requested an invitation to play, so here is hoping I get one! When I get to play the game, I will post about it on my blog.