Bet a friend afterwords that I could make a light dimmer using a pencil, a 12 volt wall wart, an auto bulb and some paper clips. I stripped the wood off of one side of the pencil lead (carbon graphite actually) and could dim the light nicely. The pencil DID get warm though not hot. Still, could have made a fire starter like that as well.

 

I had come up with the ultimate CHEAP replacement for failed glass cartridge fuses for automotive applications as a favor for a friend of mine. His GF was always leaving gum wrappers on the floor of his car, and one time a failed fuse left us with no stop lights. So I took several layers of the foil from some wrappers and wrapped it around the popped fuse and put it back unto the fuse holder. The stop lights worked for quite a few days, until a short by something in the trunk popped the fuse again. More gum wrapper repair and he was on his way. And unlike some substitute fuses, these still protected the wires fairly well. At least, nothing ever burned up because the fuse didn't clear. And he never ran out of gum wrappers