i second soma.fm
been listening to wfmu lately. they play a lot of interesting music, but there is a cool show which was incidentally featured on slate.com a week ago. here is a sample of one of the funnier ideas, where they randomly call people and see how long they can keep them on the air:
http://www.wfmu.org/listen.ram?show=15932 (starts several minutes in)
wfmu homepage:
www.wfmu.org