Last.fm is a site much like Pandora but different in the way it works. It actually does artist on demand. You set up a profile, choose the artists you like and it will play from their music and any single songs you add to your database. There is a web app and a pocket pc app also. It has a slightly different business model than Pandora. They pay licensing to the artists and publication companies per song like Pandora but put a cap on hearing one song 5 times total....unless you pay 5 dollars a month. Their library is just as extensive as Pandora and based on what I hear, they are doing better financially than Pandora who might have to shut down due to small margins after paying out royalties. Last.fm doesnt force you to hear anything other than the songs and bands you like and there is not the same suggestion setup as Pandora which has its pros and cons. Pandora has support for only a few Sprint phones and the Iphone...no third party app for streaming to phones in general like Last.fm.
Hope that helps.
I tried opening and closing the browser and turning the Rip on and off and I still get the tracks I erased ?