Along the lines of El Puerco Loco
facts about the minute impact the coriolis effect has on toilets
is a nifty little trick that clever noders
can use as one of the many ways to prove that your physics teacher is a dumb ass
Write a report on the Coriolis effect, and as your demonstration (which many teachers have begun to employ as a way to discourage plagiarism) offer to prove to the class that you are God. As evidence to your divinity, you will manipulate gravity, one of the most fundamental and powerful forces of the physical world.
Take a plastic bucket or other expendable water receptacle and put a cork in the bottom. Use tape to divide the classroom into two "hemispheres." Point out that, according to the physics we all learned from The Simpsons, toilets will flow counter-clockwise in the northern hemisphere and clockwise in the southern hemisphere. Place a bucket or bowl on each hemisphere as well, to give you something to "flush" into.
Walk around the class to show everyone your experimental toilet. Be sure to only make right turns. This will make the water flow in a clockwise motion. Go to the "northern hemisphere" and pull the cork (i.e. flush the toilet). You have just defied gravity. Repeat, making only right turns, for the southern hemisphere. Then explain that The Simpsons is not a reliable source of physics information, and that you are really not a deity. It is an impressive demonstration, worth an A in most high school science classes.