Last.fm is a great way to listen to music free and legally and also keep track of what you listen to, make new friends with similiar tastes, I like to think of it as a facebook/myspace for music fans, it has a simple yet decent layout.
So if your a user, link to your page:
www.last.fm/user/hammy27 and if your not, sign up.
Spotify is fantastic. Download it. You can have it linked to your last.fm page so it tracks what you are listening to. Much like last.fm it is a place to listen to free music, the difference with spotify is you can have playlists and stream entire albums rather than the awkwardness of last.fm where to listen to an album you have to click on each new track after the last one has finished, plus last.fm puts a limit on your plays for songs, spotify doesn't. The only real negative of spotify is ever 4-5 songs you get a short advert played, although to be honest I'm used to them and half enjoy them now
