This pen-like object turns into a magnet, an electromagnet. How it all works: When a DC power supply goes through a coil of magnet wire, some of the energy is stored around the coil in a field. Introducing my first instructable: Electromagnetic Pen!
(Doesn't actually write. Just looks close to a pen) You don't have to use battery holder, you can use a bench-top power supply!
< around ten second video!