With Last.fm on your computer you can scrobble your tracks, share your music taste, listen to personalised radio streams, and discover new music and people.
Last.fm is open source software and contains no spyware / adware. (We hate that stuff as much as you do.)
Also, if you use Skype, you can use Last.fm to set your Skype mood message to the track you're currently listening to.
These details are provided for information only. No information here is legal advice and should not be used as such.