2 Dollar Multi Touch Pad

What you see above is a multi touch pad built from a plastic bag, dyed water and a camera. The camera looks up from below and the image it sees it converted in to three areas through threshold. Light blue represents the background with dark blue being the fingers which are seen as an overlay on the screen. Pressure points are seen as another colour and when the pressure points show up they are recognised and translated accordingly. More technical details can be found at 37Signals linked after the video demonstration below. On to the practical side of this… I doubt anyone would want to carry a plastic bag of blue dye around with them, but its still cool and well worth checking out.

Via: 37Signals