It would be really cool to set up my holographic display with one of these. Have a transmission hologram of a keypad lit with a single laser diode that projects the keypad 12 inches in front of the hologram. Have each of the keys on the keypad control a light to each of my holograms that are displayed on the wall. Thus a viewer could walk over to the keypad and and virtually tough the keypad corresponding to the hologram that he wants lit up.
Such a simple idea but a great one. This should make it big. The infrared detectors used on lavatory urinals would probably do the trick with some tweaking.