[Caution: loud music, starts instantly]
Since neckwarmers can’t just be neckwarmers, this guy put together a LilyPad Arduino neckwarmer. A simple neckwarmer was modified with lights, a LilyPad Arduino, and a light sensor to make the lights blink when it’s dark. The maker claims that it will keep you warm in the winter while biking, at the same time keeping you visible to drivers. I guess reflectors and simple blinking lights aren’t good enough anymore.