Rather than visiting a kiosk to rent a bike, you'll be able to use a smartphone app to locate some available wheels, with position information broadcast by a built-in GPS. Once you find a bike you want to rent, the system will send an unlock code to your handset, which you'll enter into a handlebar-mounted PIN pad.

ENGADGET: NTT DoCoMo Shared Bicycle Initiative hands-on (video)

Activated by pulling out a grenade-like pin and palming an embedded finger pad, the Armstar BodyGuard 9XI-HD01 sparks a loud and visible arc of electricity between its wrist-mounted taser spikes, a sight that inventor David Brown hopes will encourage would-be crooks to surrender.

ENGADGET: BodyGuard stun-glove leaps out of comic books, into the arms of LA Sheriff's Department