There are some great pieces of creative work being developed that take advantage of the interactive features associated with touch technology. I personally differentiate dual touch from multi-touch below, but concede that there is an amount of blurring. Perhaps the distinction is irrelevant, but I will go on record here to start the debate:
Dual touch is an interactive experience involving two independent users, each sharing the same interface and possibly collaborating. It can also be a single user using both hands independently. Great for collaborative work.
Multi-touch builds a level of intelligence into the interface with plural-point awareness and is often used to implement advanced functionality, think pinch to zoom on a smart phone. Great for augmented software functionality as long as you have opposable fingers – sorry monkey man…
Hush studios have spent some time understanding how these types of touch can be utilised to develop a broader collaborative touch experience.
There are the usual technological elements integrated into their fantastic, playful solutions: MS Kinect, MacBook Pro, Corian, Spandex screen, rear projection, tiled screens.