…a novel, inexpensive, stereoscopic technique for generating 3D images from cellophane on a liquid crystal displays which are most typically used for a laptop screen or a camera phone screen. Stereoscopy requires independent manipulation of the left and right eye views. Our technique takes advantage of two facts; the first is that the light from the liquid crystal display of either a laptop computer or a camera phone is polarized light, and therefore we can easily manipulate its transmission with a polarizer sheet. The second fact is that a cellophane half-waveplate can change the direction of polarization of light. [via] Link.