Actually, it is called the Kandel Heeter. It can be found here. It collects and concentrates the heat from a candle (that would normally escape straight up to the ceiling) and converts it to radiant heat. This guy is selling them for $29.95 each. I would love to make one, but for that price, I might as well buy one.
Remember, this would only heat a small well insulated space. But, still, a really cool idea.