Lamperd, a "firearm training system" company, has patented a bracelet that delivers debilitating shocks when remotely triggered. Their killer app for this is aviation safety: they're proposing that the TSA could force everyone who flies to wear one of these and then flight-attendants could zap us into a stupor if we turn out to be Al Quaeda.
A method of providing air travel security for passengers traveling via an aircraft comprises situating a remotely activatable electric shock device on each of the passengers in position to deliver a disabling electrical shock when activated; and arming the electric shock devices for subsequent selective activation by a selectively operable remote control disposed within the aircraft. The remotely activatable electric shock devices each have activation circuitry responsive to the activating signal transmitted from the selectively operable remote control means. The activated electric shock device is operable to deliver the disabling electrical shock to that passenger.
Best part? They're Canadian! Oh, my countrymen, you have a wicked sense of humo(u)r.
Link to patent, Link to Lamperd FTS site
(via Schneier)