Jamendo Rhythmbox plugin
Jamendo is a rocking musical portal from where you can listen and download a huge quantity of free (as in freedom and/or as in free beer) music. Like the Magnatune plugin, it gives you the ability to listen (streaming) and download all the Jamendo library (except that here you don't have to pay anything!). Download is done using Bittorrent and you can choose if you prefer OGG or MP3 files.
So you can very easily enjoy more than 20000 tracks from 1600 artists (that means more than 58 days of music!) and new albums are added each day. Furthermore, as you can see on this screenshot, the plugin interacts with the albums cover component.
 Very cool rock band of a friend of mine