On the subject of interesting magnetic effects, a lot of people don't know that pretty much all matter is magnetic, just that the strength of the interaction is a lot smaller than what we're used to with ferromagnets.

All materials exhibit a diamagnetic (pushes against the field) effect, but in many materials, that effect is overwhelmed by a competing paramagnetic (pushes in the direction of the field) effect. Most of the things we call "magnets" exhibit ferromagnetism, which typically produces much stronger forces than either of the previous two.

H2O is particularly interesting, because it's actually diamagnetic, and will push away from magnetic fields. Given a strong enough magnet, you can have a lot of fun with this effect by putting common water-filled objects in its field: http://www.ru.nl/hfml/research/levitation/diamagnetic/