Your search for the "multi-touch screen" tag brought up 2 results:

E-Zine: Usine Multi touch demonstration

Usine is a nifty piece of software that can act as a host or VST and is geared towards live performances and multi touch screen interfaces.

E-Zine: DIY Multi-touch screen

Building your own touchscreen has been quite the hype on the interwebs. The DIY projects out there can be very good and it does not have to be that expensive!