Came across this on this and really liked it. Knowing how hard it is to get mobiles to do what you want to do, hats off the the guys who created this. The "Making Of" video is worth a watch too and you can read more about the effort here

Experience Mobile Mobile from James Théophane Jnr on Vimeo.

The tune, though it's "Carol of the Bells" is nearly now more widely known for the Garmin ads - amazing how "brand association" works.