Now that LCD projectors are available in pocket sizes, I can’t imagine why somebody hasn’t incorporated one into a cellphone or compact camera.
Today’s invention is to use a pocket projector to project a part of an image or video sequence into the scene being photographed. This offers numerous extra opportunities for digital creativity. The captured images could be processed in-camera and then superimposed, in some modified form, on the target scene.
This might be done with a section of video, so that, for example, a new composite movie could be created of someone dancing at a given instant, together with their movements of a half-second ago.
Similarly, projecting a grid of fine lines onto a scene and then recording the result could provide a cheap, quick alternative to laser scanning for the extraction of 3-D data.