Last.fm is not just a Internet Radio it has many other interesting features.
Some of those features are,
* Personal Music Profile
* Music Charts
* Recommendations
* Groups
* Internet Community
In order to build your profile you need to get a plug-in for your favorite music player... Plug-ins are available for all most all the Music Players..
BTW with Last.fm you can build your own Personal Radio Station so your friends can listen to it.
This is my last.fm profile:
http://www.last.fm/user/kesara
And my Overall favorite artists chart is
This is going out all the Last.fm users... 
Post your music profiles here.
Ah. I almost forgot the URL to the main website is
http://www.last.fm
