In a prime example of technology for the sake of technology (and with sexy results), welcome the Reactable:
Wikipedia says, “The reactable is a round translucent table, used in a darkened room, and appears as a backlit display. By placing blocks called tangibles on the table, and interfacing with the visual display via the tangibles or fingertips, a virtual modular synthesizer is operated, creating music or sound effects.”
It’s not exactly news, the original design came out in 2005. Since then it has been drooled over by computer music enthusiasts and purchased by Bjorks everywhere.
Technically the design is free. The software and full explanations are on the developers’ website. The only problem is the cost of buying a projector, a video camera, and a giant translucent surface.