The watch this guy's wearing was made by Armatix, the company who designed his high-tech gun. Poor fellow can't ditch the ugly accessory though, because the $US10,000 gun won't fire without it.
Basically the gun is disarmed and a red LED lights up unless the corresponding watch is close enough to send a wireless signal. While I really don't see a high demand for it, Armatix's .22cal weapon will be shipping next month for 7,000 euro, which is just under 11k in Australia. The watch is probably included. [Wired]