Have you checked out HoloToy’s iPhone app? It’s the work of one man — Ben Hopkins — who’s taken advantage of the brain’s visual processing expectations to make images appear 3D, even though they’re actually flat images. He uses the angle of the device to present a believable 3D scene. It’s really quite remarkable.
You’d think it’s absolute rubbish… until you see it. Have a look at these two demo videos: