Listen to Mixtapes on Your iPhone with 8tracks

Event though it has a retro name, 8tracks is actually a service that allows users to create their own mixtapes that have a maximum of 30 minutes and are based around a theme, mood or subject. These can be uploaded through the 8tracks site or imported from SoundCloud. These then can be played from a variety of devices.

The iPhone app features:

• Easy ways to find just the right mix: mood, occasion, genre, or artist
• You won’t hear the same songs time and again
• You’ll discover new music you’ll love, no matter what you’re into
• Each mix has a personal touch, including title, photo and description
• You can "follow" the DJs you love (a la Twitter), or "like" or comment on their mixes
• No annoying audio ads (and, for the next month, no banner ads either :))

With the recent update, the app now supports the iPhone 5 and iOS 6. 

8tracks is completely free and available in the App Store [iTunes Link].