The Spotify streaming music service started in Europe, but has been steadily expanding its reach to more regions. Spotify offers a truly enormous library of more than 15 million tracks. And it shoots them to your mobile device at 320 Kbps, a higher rate than some other services -- the result is better sound quality. With premium service, there are no ads, and you can access exclusive content like pre-release tracks.
Spotify has a group collaboration feature that lets you and your friends create playlists together. Another feature lets you download playlists from your computer to your phone so that you can listen to your tunes when you're out of range of an Internet connection.