iPoint from NaviSense.

iPoint is a new computer pointing technology developed by company NaviSense. The iPoint™ is a small motion sensing mouse device which mounts to the keyboard or computer.

By simply moving your finger in front of this device, your able to control the cursor movement in your computer. A first finger movement acquires navigation control of the cursor, and a second finger movement activates single and double click behavior.
The iPoint™ tracks finger movement and finger motion behavior to navigate and control a cursor on the computer display.
Navisense aims to increase the efficiency by which users interact with email, computer applications, computer games, search engines, and data entry systems.

Here is a short video of the device in action: