check out this site:
www.pandora.com
it allows you to listen to stations for free where you type in an artist and it will play them and artists similar to them. if you sign up (still free) then you can save artist stations and create mixes of artists. it has a pretty good number of songs and you shouldn't hear too many repeats unless you listen to it a lot.
sorry, this is like a commercial, but it's a cool site and a good service, and i know most of us here are at our computers a lot and can get tired of the same old music.
(i also realize this could go in music, but then no one would see it!)
any other good internet radio sites?