We've already shown you how to transform your Raspberry Pi into a Pandora jukebox. If Spotify is your streaming music service of choice, you're in luck now too.
Wouter van Wijk published a clever bootable image that turns your Raspberry Pi into a remote Spotify server with little to no tinkering. The software itself has no GUI, but you can control music playback from any browser or MPD client on the same local network. The package supports USB audio if stereo won't cut it, and offers AirPlay support too. You will need a Spotify Premium account for this to work, but if you have one and want a remote playback device, this looks like a perfect option.