Pavel Jetensky has created the 3D keyboard project that is kind of like 8pen in 3D and takes input from Kinect. Generally speaking 3DKeyboard is an application utilizing Microsoft Kinect, that enables you to type text with moving one of your hands in the air.
Keyboard consists of 7 cubes in a cross-like pattern. Crosses are parallel to
user screen, so normally you see only front cube (blue) and middle layer (green)