Cold Heat soldering irons are pretty cool. They heat up in seconds and cool down just as quickly. [photozz] shows us how we can make one from stuff we probably have sitting around right now. Cold Heat soldering irons work off of resistance, the tip material heats very quickly when electricity is passed through the two halves. Upon assessing what he had lying around, [photozz] realized that graphite would work much the same way.  He modified a regular soldering iron with a new two piece graphite tip, and powered it with an old pc power supply. The end result is quite nice, though it still needs some kind of temperature control.  You may recall seeing other electrical uses for graphite, such as making quick and dirty light.