Most photography studio strobe lights are what they call "slaved," or light-triggered by means of internal sensors; when one of them fires, all of them will fire simultaneously, so you don't have to plug a wire from your camera into all of them during multiple-light set-ups.

NYU Interactive Telecommunication Program student Adam Harvey has harnessed this simple technology to devise a brilliant anti-paparazzi device that goes well beyond Ashton Kutcher's Tweets: A purse with a flash sensor and flash. His clutch purse contains a sensor that is triggered by a flash going off, and it instantaneously fires its own flash, completely ruining paparazzi shots.

Harvey is currently working on the patent and hopes to have the bag ready for sale by Spring 2010.

via gizmag