I absolutely love pandora.com BUT you can't listen to anything on demand, you have to wait and listen to whatever station.
I like the fact that it helps let you discover new music though.
Another place I found was dizzler.com, you can add pretty much any song to a playlist but I'm nit sure how they play the songs....I think it might be from other users and so some of them never load or load very slow.
what about you
