A team of Spanish researchers at the University of Lleida have developed a way to detect false coins using mouse sensors, detecting particular patterns in two Euro coins, which at the ongoing exchange are about $150,302 each.

The system rotates the coin, sampling its surface using a 30 x 30 pixel resolution optical sensor (although it can work with lower resolution sensors, as well as with webcams). Then it compares the samples to a stored model, giving you the nay or the yay. [El Mundo—In Spanish]