Fun Things To Do With Magnets
Evilmadscientist.com has a post on cool things to do with magnets. Some of the included tricks are taking out batteries from hard to remove places, finding studs in a wall, making a compass, and making a fridge pen.
You can usually buy magnets from any hardware store. If you do not feel like buying a magnet, simply break apart an old speaker. Amazon also carries magnets.