Magic Playlist - Get the playlist of your dreams based on a song
Pandora iMessage App - Say it with Pandora — Send and receive songs in iMessage
Spotalike - Spotify playlist with similar songs, according to Last.fm
Pandora Premium - On-demand music. Pandora's answer to Spotify.
Spotify - Map shows when two people play same song at same time
Pandora - Pandora Radio is a free (ad-supported) internet radio founded in 2000.