Exaile is a media player aiming to be similar to KDE's Amarok, but for GTK+. It incorporates many of the cool things from Amarok (and other media players) like automatic fetching of album art, handling of large libraries, lyrics fetching, artist/album information via the wikipedia, last.fm support, optional iPod support (assuming you have python-gpod installed).
In addition, Exaile also includes a built-in shoutcast directory browser, tabbed playlists (so you can have more than one playlist open at a time), blacklisting of tracks (so they don't get scanned into your library), downloading of guitar tablature from fretplay.com, and submitting played tracks on your iPod to last.fm.
Similar applications:
Amarok, iTunes
Website: