Last.fm is an open-source application licensed under the GPL, allowing you to listen to Last.fm radio stations and submit the songs in the same time. For those of you unfamiliar with Last.fm, it's a great social music community, allowing you to submit songs you currently listen to, statistics, forums for bands or music styles (or even more: Amarok has a group, most major distributions also, and you can start your own group about anything, match people and discuss), together with information for each artist, open for anyone to edit, just like the Wikipedia style.