Try Blubster
I agree with points on both sides of the infringement/copywright issue....
However for me it comes down to a few steps....
First of all on all those file sharing you are going to usually find the top 40 etc with the artists that are already making millions.
Second if you do stumble across some lesser knowns all downloading their music is going to do is make you want to buy their t-shirts...go to their concerts etc etc etc. In the end it is the best advertising for some musicians whose music might never reach the other end of their country but with this is raeches all over the world.
As far as the theivery idea......music is art and art was created to be shared (This opinion comes from a novice musucian/songwriter artist and if I were to make it big it would be more to get my thoughts and ideas out there than to make money....the money would come from the live shows anyway)