Jajouka is a nice GUI interface for those with GiantDisc jukebox systems. Jajouka creates playlists for a music player (eg. xmms, beep-media-player, etc). It reads mp3 id3v1, id3v2 and ogg music tags and stores the information on a GiantDisc server (see http://www.giantdisc.org).
The GUI is rhythmbox based, but with a proper playlist window.