Arrange these magnets just so, and they float in thin air. Forty bucks from Scientifics Online!
Use your knowledge of magnetism and your scientific skills to arrange the magnets on a thin sheet of sheet metal so that alternating poles create a strong magnetic field gradient. This gradient centers the pyrolytic graphite material of the magnets for levitation. Pyrolytic graphite is 10,000X more diamagnetic than most common diamagnetic materials like water, and these thin slices are extremely light and can be made to levitate.Diamagnetic levitation kit [Scientifics online via RGS]