Microwave Weapon
I will keep it very simple. This is from a "Glubco" page.
Take your television apart.
Take your microwave apart.
Leave all the electronics in tact.
Build a metal box.
Put it around the thing that makes the microwaves. Note from John: this is called the "magnetron". It may look something like this: 
Attach the box to a natural ground.
Put a 1 foot length of PVC pipe extending from the "nozzle" of the magnetron.
Point it at something useless and preferably made of metal and plastic.
Get away.
Hide behind metal.
Turn it on.
Fear what you have created.
Glubco takes no responsibility for people doing stupid things with appliances.
Glubco - Deny Everything Copyright 1997.