The always curious people over at technoHOLIC recently purchased a neodymium magnet and a few other supplies from our online store for a demonstration on liquid body armor. They wanted to show that a magnetic field could cause certain liquids to behave as solids. Okay, I have to admit that I knew nothing about liquid body armor before clicking on the link, but technoHOLIC's article on magnets is very, very good. We tell people that our neodymium magnets are "super strong," but sometimes they just have to experience it for themselves (as they point out in the article).
The magnet didn't just transform our iron-and-oil fluid into a solid — sometimes, its pull on the fluid cracked the petri dish holding it. Once, the magnet unexpectedly flew out of a videographer's hand and into a dish full of dry filings, which required considerable ingenuity to remove. It also adhered itself so firmly to the underside of a metal table that we had to use a pair of locking pliers to retrieve it. When we decided it would be safer to keep the magnet in a pocket between takes, people wound up momentarily stuck to the table, a ladder and the studio door.
If you're doing a science fair project on magnets, this technoHOLIC article on magnets is a must read.