You may want to look into the squeezeBox and similar devices. I'm not sure exactly what functionality is available, as I don't have one.
I have a Squeezebox Boom (ok, the wife does
), and it's great. In fact, I like it enough I'll eventually get other squeezebox products for other music-only areas. The Squeezebox Touch looks like a perfect option to mount on a wall and run to powered speakers.