Slacker Radio is now available for Android as a free download from the Market application on the Android smartphone.
Slacker Radio is an advertising-supported streaming radio station that lets you stream music of different genres from your android mobile phone. It's a smart technology, which is to say that it learns your musical preferences when you vote on the songs you hear. Vote yes on a song, it feeds you similiar music. Vote now on a song or artist and you won't hear them anymore.
It's completely free, but you can buy into a subscription serveice for $20 a month, and this frees you from advertising, and lets you skip songs. Go for free, and you can only skip so many songs per session, before being forced to listen to all songs. The audio quality is pretty good: clear highs and bassy lows.