In college we cooked a lot of hotdogs with a 'lectrocuter. Cut the female end off a cheap extension cord and strip the wires. Wrap each end around a fork handle. Stick the two forks into opposite ends of the hotdog and plug it in for 45 seconds or till the dog splits. Yum.
Somewhere there was a story about making a lightshow with a grape in a Mwave. I tried it but its been a while and I am not sure of the exact procedure. Seems like you cut a grape almost in half and open it like a book. Leave it flat sides down on a plate and cook it. It lights up like a sparkler (I might be leaving something out).
The egg in the Mwave: I wrapped an egg in probably twenty paper towels and cooked it for 5 minutes. At around 3 minutes it blew up, ripping thru all the paper towels and blowing the clear window panel across the kitchen. Microwave mever smelled right after that...
Cooked a big roach. After a while he just stopped moving. Not much of a show.