A couple internet-broadcast radio stations I'd recommend:
minnesota.publicradio.org/radio/services/the_current/
Really excellent assortment of music, ranging from Twin Cities-based up-and-coming acts to underground hits to folk-rock legends, blues, jazz.. all kinds of stuff. I have a lengthy list of artists I swore to investigate further after hearing their stuff here.
http://radiomilwaukee.org/
Along similar lines. Lots of stuff I hadn't heard before.
I'm really enjoying what I've heard by <a href="http://www.salimnourallah.com/>salim nourallah[/url]. light folk-pop stuff, very pretty.
<a href="http://www.myspace.com/leominor/>Leo Minor[/url] is a fun, electronic/indie/pop act from Milwaukee. Catchy stuff, somewhat 80's-esque. Well worth a listen.

I also recently came across a Spanish performer named who does some REALLY lovely stuff,
Dani Flaco. It's all in Spanish (as is his webpage), but its great enough I just don't care that I can't understand it. :p