I played a game a while ago with a great GM who would do random pickup games with whomever was around several times a week. You'd just send him a message and play your character in a text based evolving world. I'm looking to find something like this again. I'd love to play a game at random times and have a constantly changing world with several players that rotate in and out. It was all text based, and it was quite amazing. I'd prefer pathfinder, but I suppose if I found a GM that was willing to do that I'd do just about any format.