If you want another fun and deadly thing to do get a power pack like they have in schools set it to its highest settings and attach it to some graphite rods via crocodile clips (pencil with the wood removed works well). You have just made a massive sparkler and if held together for a long amount of time they fuse together not really sure how as it takes a temperature of over 3500 degrees to melt graphite but it happened.
You can make a super heated wire cutter by adapting a motherboard 24pin off of a psu and some wire with quite a large gauge then attach the negative and positive to the ends of the wire making one slidable. As you move then ends closer the wire will get hotter because of electron density and concentration of energy on a non insulated wire. Burns through pretty much anything and gives lovely straight lines if your hands are steady I sometimes use it to cut wood as a saw is way to boring.