You can convert a standard MS keyboard to a Minority Report style touch pad by removing the outer case.

There are 3 plastic layers. Two, on top and bottom, have the contacts that touch each other to form a keypress. The middle one has holes where the keys were, so if you leave the keyboard flat, the contacts are a quarter of a millimeter away from each other, held there by the middle layer. However, press any spot, and the contacts touch, the equivalent of a keypress.

More pics: Flickr [Via: HackedGadgets]