I'm trying to get the guys in #mobitopia to gang together and create a mobile MUD. We've been batting around this idea for well over a year, but I think now is the time. With most newer phones supporting decent J2ME sockets support, creating a basic J2ME MUD client would be pretty straight forward. Craig pointed out Coffee MUD which is a Java based MUD app ready to launch... it'd be a no brainer to get this up and running.
In case you're not hip with the lingo, MUD stands for Multi User Dungeon. Basically it's an online text based adventure like Zork, but multiple users can participate. You're given a basic storyline (in this case, a D&D like world) and you can move around the world with basic commands like "north, south" etc. When you're in the same "place" or "room" as someone else, you can see them listed and chat with them. You can gang up and go out and kill monsters together, etc.
You can try the Coffee MUD demo here.
Because of the limited vocabulary needed to play these games and the ability to scale (it's just text, after all) it's a perfect for mobile phones. I haven't played a MUD in years, but they're still very popular and after playing on the phone for a bit we could learn what to tweak to make it more "mobile friendly". Maybe some "quick commands" in a menu for directions and logging in/quitting. Also maybe the descriptions are a bit long. Since the code for CoffeeMUD is OSS and Java, it'd be easy to get in there and tweak the displays as well.
I'm not exactly sure how, but I'd probably want to try to limit outside access to the server so it was just a phone thing. I'm not sure if there would be any real advantage to PC users, but you wouldn't want someone with a full-keyboard getting some sort of bonus just for that reason.
Anyways, another project to think about! If I only had time for all this stuff!
Later: Updated with a screen shot of me accessing the site with Putty for Symbian!