These are virtual keyboards that can be projected and touched on any surface. The keyboard watches your fingers move and translates that action into keystrokes in the device. Most systems can also function as a virtual mouse.
Market Size
In addition to replacing the two million foldout keyboards sold for Palm and other handhelds to date manufacturers hope to take a significant share of the $1.6 billion dollar PDA market, the $50 billion dollar desk workstation market and the $23 billion dollar (by 2004) smart cellular phone market.
Applications
In addition to small devices projection keyboards could be used to create a control-panel projection that offers virtual knobs and switches for use in hazardous environments, as well as in medical markets where sterile data entry is a concern.
There are 4 companies that are bringing products to market in the next year or so:
Tooth Implant
Projection Keyboards
see also The Audio Implant