The tip of your pencil (you do remember pencils, right?) is made out of graphite. Break that stack of carbon down into one-atom thin sheets and you get graphene, a recently isolated material that's got all sorts of fun properties—including the ability to conduct electricity faster at room temperature than anything else known to humans. It's pretty nifty and you can make it—with the help of masking tape—using this handy step-by-step guide put together by Scientific American.
(Via Mark Changizi)