The Bird is a tool for controlling a point in 3D space using one hand, designed primarily for use in virtual reality. The Bird stays directly in front of the user's palm, and can be sent farther away or brought closer by extending and closing the fingers. As with a 2D computer mouse, the pointer finger is reserved for selecting, and its extension is ignored for tracking. The name Bird stems from its similarity to a computer mouse, named for an animal occupying the ground, evolved with the addition of a third degree of freedom into an animal occupying the air.
See more on the Media Lab project page.
The Bird is the subject of a paper currently under review at CHI.