Spring 2005 I produced a pair of Keycases to celebrate the launch of
keycases are designed to only allow people who are excited about driving
the car to do so. A galvanic skin response sensor on the front of the
keycase measures the driver's excitement level (it's not very scientific,
basically it measures minute changes in sweat levels on the surface
of the skin, you can read more detail about it here).
If the reading is sufficiently high then the case will unlock (if not
then it remains shut).