I searched the archives but couldn't find a previous post. Anywayz, as I recall, bring in a continuity tester that buzzes and/or lights and ask the kids if they think various things are good conductors or bad conductors. I had some oddities like a thousand watt metal halide lamp, 600kcmil compact 4 conductor with ground MC cable, inch and five eighths coax, and a chunk of 345kv/2222a cable to show how big some stuff gets.
