This site is one of the more out there catalogs of fun things to do with microwave ovens. Sites like this help establish the microwave as the single most exciting appliance in a typical house.
Several college playing-with-fire "experiments" with details on how to recreate them. Four of the five are merely good, but number three, "The Act of God" is standout.
You might want to hold back on doing this one if you want your security deposit back when you move.