Not sure if this is exactly what you’re after but Sonos for music is really really nice. http://www.sonos.com
Their dedicated controller is very small and nice. They also have an iPhone app so you can use your iphone to control the music.
We used a service to rip all our cd’s to uncompressed flac, and the Sonos plays those (and our miscellaneous mp3’s from back in the day), but it seems what we really use all the time are the Rhapsody and Pandora music services. Sonos hosts those very seamlessly.
Sonos is coming out with an iPad app too very soon now which is expected to be quite good.
Overall we’ve found almost anyone can use the thing to play the music they want to hear. It is great for entertaining to just be able to empower your guests to play what they want, while you concentrate on entertaining.
