On December 3, 2011, I debuted my new multi-touch live PA rig at the From 0-1 Artist Showcase. This new software began as a port from Radial, a computer-vision-based music performance package I developed on openFrameworks, Magnetic, and FMOD. The rendition here is now a Cinder application which uses Windows 7's native multi-touch and a capacitive screen. The accuracy, performance, and ease of setup is light years beyond Radial.
Relevant links, if interested: