Gravity is a pen and pad that allows to sketch in 3D space using augmented reality. The cool patent-pending system hardware and software system has gone through several working prototypes and now they are looking to start manufacturing. Check out the video—it's pretty cool.
Gravity's creators—a group of four Innovation Design Engineering students of the Royal College of Art, London—think that it can really change the creative process for designing 3D objects.
I do like the idea of using the pad as a 3D plane that I can rotate around in order to build new facets of an object. It may be a good way to intuitively create 3D sketches that can serve as a base for 3D modeling in the computer.