LEDs are cool. Literally. And I’ve been eagerly watching their adoption from traffic lights to car tail lights to flashlights and light lights. This holiday season, LEDs are gaining in popularity as bulbs for Christmas lights. Although they cost much more than your regular string of incandescent bulbs, the LEDs use less electricity and can last for 200,000 hours. One drawback I can think of is the lack of the melting effect that creates little holes in the snow when you turn your hot lights on under a blanket of freshly landed white flakes.