Jango Radio is a free personalized radio that streams music to your iPhone/iPod/iPad. Start with an artist you like and Jango will create a custom station that plays music from the artist you requested as well as music from similar artists. Or, if you prefer, enjoy Jango genre-stations like Top 100 by Jango, Love Songs, Hits from the 80's and many more.
Jango Radio is free and the songs are full length songs (not samples). It is not a time-limited trial - the application is yours to use for as long as you'd like.