I just found this site today that has a few online multiplayer games. One of these games consists of a big blackboard where different "guests" can come and draw whatever they want, simultaneously. This is pretty cool because you get to see what other people draw + their different styles, and man let me tell you, those asians are so damn good, they made my drawings look like shit but I don't care. I'm still having a blast... Me & Patrick where there for a few hours, in a more "private" room (there's 10 rooms) drawing stuff and guessing what it was, like Pictionary or whatever it's called.
So yeah, it's creative & fun, you should check it out.
Here's some artwork from multiple guests.