T(ether) your digital collaboration
Creators Matthew Blackshaw, Dávid Lakatos, Hiroshi Ishii, and Ken Perlin call T(ether) "a tool for spatial expression" that "acts as a window affording users a perspective view of three-dimensional data through tracking of head position and orientation."
So what this means is you can use the iPad to view a shared virtual space where you can manipulate objects with the other hand using a special glove. You can draw 3D shapes, rotate, pinch, zoom, and examine them in a multi-user environment. Two people looking through their iPads at a grid of virtual cubes can both reach in independently and manipulate them at the same time.
A cool concept that illustrates another way to do collaborative design in a virtual space.