Waft

Waft plays streaming Internet radio stations. For free. Instead of picking stations from an arbitrary list of limited stations, Waft lets you add any station from standard .pls or .m3u playlist files via iTunes File Sharing. (Of course there is a built-in arbitrary list of stations to choose from to get you started.) Waft plays beautifully in the background. Most internet streaming stations are supported including those broadcast via Shoutcast/Icecast and Live365.