Realtime Online Jamming
I'm not affiliated with the site, but I've been visiting http://onlinejamsessions.com recently. There aren't that many users yet, but the jamming is real time and the people that do come regularly are great. Come by, start casting audio, and jam with some folks.
Our songs also have the standard pop format: Verse, chorus, verse, chorus, solo, bad solo. All in all, I think we sound like The Knack and the Bay City Rollers being molested by Black Flag and Black Sabbath.