SurfaceDJ from Vectorform was one of my favorite applications shown at PDC.  Not only does it involve Multi-touch, Surface and music; but it is an example of a new form of collaborative application.  Joe Engalan and Markus Sheldon build up the music, keep it alive and then break it down in real-time while working together at the Surface table.  I want one!

Check out Vectorform's Surface blog to see some of their other Surface applications. Yes, they are the ones behind NBC's Electoral application.

Surface beats with Vectorform