The SafeTurn is a wrist-mounted LED light for bicyclers that flashes when it senses the rider’s outstretched hand. I can’t quite determine if it has a directional blink, changing depending on the angle of the cycler’s arm, but it would certainly make sense that it would. You can find out for yourself in February, when the patent-pending Australian invention will be released.
Safe Turn Indicator [TreeHugger]