I just found a new site devoted to major metro areas around the country.
check it out at http://www.musicpostusa.com

It's brand new. It looks cool and the search feature evidently is unique in the way it ties all the metro areas together without having to login to many different sites serving only one area at a time. You can limit your search to one metro area so you don't get 150 results all across the world when all you need is a bass player for Friday night.