We have to admit, we never thought of this one -- and it's pretty, pretty slick. Instead of using time-coded vinyl to interface your turntable with your computer as with Final Scratch Pro or Serato Scratch, Nicholas J. Bryan's Mopho DJ uses an iPhone. That's right, our man at Stanford University literally affixes his smartphones to his decks via a perspex disc and some sort of adhesive. The smartphones each run an app which sends accelerometer and gyroscope data to a computer, which then adjusts playback of your music accordingly. It's still a work-in-progress at the moment, but if you're in Oslo the first week in June make sure you check it out at the NIME (New Interfaces for Musical Expression) conference. This is definitely the kind of iOS location tracking we can get behind! Check it out on video after the break.