Recently passed the 2000 albums mark and currently indexes 2005 Creative Commons licensed albums. The site offers some great features that make it easy to share and discover new music. You can browse their album collection by genre, country, popularity or tags, for example. If you find an album that you like, you can share it on your blog, write a review, or donate directly to the artist. Some artists will even include the list of people who donated in the booklet of their forthcoming albums.
A great site for both artists and fans. Everybody wins, except for the big record labels of course. The albums on are available in MP3 (~200Kbps) and Ogg Vorbis (300Kbps), and can be downloaded with your favorite BitTorrent client or Emule.