I believe there is a Netgear NAS unit that can run the squeezecenter software natively so that a computer isn't required to be running.

Controlworks module:

• Browsing or searching the SqueezeServer's music library by songs, artists, albums, or genres
• Control playback, including play, pause, track previous and next as well as the ability to skip to specific locations within tracks
• Shuffle, repeat and random controls
• Playlist creation 
• QWERTY Search capability
• Internet radio
• Dynamic Graphic support for album art
• The ability to access the external digital inputs when used with a Transporter [Not applicable for other models]
• "My Apps"
  • Pandora
  • Rhapsody
  • Slacker
  • Last.FM
  • Napster
  • Media Fly
  • Sirius Internet Radio
• Search support with Rhapsody, MediaFly, and Napster
• Station creation for Pandora and Last.FM
• Love and ban support for Pandora and Slacke