I have discovered the next great online game! It's quick, it's easy, and it's got an infinite number of possibilities.
http://www.musicmaven.lunarpages.com/
Music Maven lets you create your own band (select from one of up to 50 genres), manage the group, and do just about anything else with them. The goal is to tour successfully, make top-selling albums, and acquire groupies and such.
It's a very easy game to play, once you figure out what you're doing. The possibilities for bands are limitless, and actually quite humorous. Right now I'm managing a boy band called "Boy Town." They're getting all the songs worked out for their debut album. They'll soon take the Top 10 charts by storm.