pCubee - a personal handheld 3D Cubic display
Researchers from the University of British Columbia have designed a personal cubic head-coupled 3D display that shows reactive 3D scenes. You can interact with the cube in 4 different ways: view a static scene, navigate through a large landscape, play with colliding objects inside a box and use a stylus to manipulate objects. This is rather cool, check out this video:
More information can be found at the research group's page.