This video offers an overview and demo of Seth Sandler's AudioTouch - an interactive multi-touch interface for computer music exploration and collaboration.
The interface features audio based applications that make use of multiple users and simultaneous touch inputs on a single multi-touch screen. A natural user interface where users can interact through gestures and movements, while directly manipulating musical objects, is a key aspect of the design; the goal is to be able to interact with the technology (specifically music based) in a natural way.
Users can load, exit, and move musical applications using gestures as well as have a multiple applications operate within the same work environment.
The design is built into a table that hides all the hardware necessary for tracking multiple inputs as well as displaying visual feedback on the touch surface.
See Seth Sandler's site for more info on Audiotouch.