I just found a site that is trying the concept I have had in mind for several months but lacked motivation, time and interest from others to further it. The site lets you set up a membership and then audition for projects started by other musicians or upload your project in search of others to add to it. It is a really neat idea that I think will really take off once the word of mouth spreads. Imagine adding ethnic instruments or creating music that requires a band and all on the net. Check it out and sign up if interested.

http://www.nowrecording.com