If you would like to directly control mouse input to a projected computer display with a laser pointer, all you need is a DV camera and Mouz.
Plug the camera into your PC using Firewire and point it at the projected screen. Then run Mouz and calibrate it by specifying the corners of the screen , Mouz will then motion track the movement of the laser across the screen, map this to the correct screen coordinates and raise normal mouse events on the PC.
Your laser must be bright enough to be the single brightest point in the camera's field of view, ie brighter that the projected image of the screen.
