Our friend Con sent me a link to Pandora and I have to say I am pretty amazed. Put in your favourite bands and let the site act as your own personal radio station. It will throw up songs and bands that you perhaps have never heard of before and you can give songs a "thumbs up" or a "thumbs down" and it refines its music. Very quickly I found that it rarely played a song I didnt like and I am now downloading the songs via LimeWire.
Do yourselves a favour and check it out... and yes, its free!