For those of you who would like to see the next step in screen interaction, check out this video from the team that is experimenting with this new technology. For a more detailed description and a lot a technical jargon go to this website.
The simplest way to explain how the system works, Lanman says, is to imagine that, instead of an LCD, an array of pinholes is placed in front of the sensors. Light passing through each pinhole will strike a small block of sensors, producing a low-resolution image. Since each pinhole image is taken from a slightly different position, all the images together provide a good deal of depth information about whatever lies before the screen.
An array of liquid crystals could simulate a sheet of pinholes simply by displaying a pattern in which, say, the central pixel in each 19-by-19 block of pixels is white (transparent) while all the others are black.