JamNow is a new collaboration site for musicians to work together online.
You can schedule and post a live jam session or join an existing session that had been created by another user. Connect to jam sessions with your computer microphone or with your own pre-amp mixing board, collaborate with others and connect to make music in a new way online. Jam sessions can be broadcast live and allow for listeners as well as collaborators. You can find posted jam sessions to listen to as well, rate them, add other users as friends or add yourself to their fan list.
The process of setting up a jam session is somewhat complicated for new users, considering the current state of JamNow as a newly launched site. With the entire purpose of the site revolving around collaborative jam sessions, it's difficult to get this community started, and will require a lot of users to be able to offer something to both musicians and listeners. That being said, I didn't find anyone to jam with, or even any jam sessions to listen in on. A better interactive schedule that allows for users to better follow musicians they like would be beneficial to both artists and fans.
Other music collaboration sites include JamJunky and Indaba.