Vertical Velocity (or V2) is an Impulse Coaster at Six Flags Great America which is a coaster that is launched forwards and backwards using electromagnetic motors. You can see the magnets above the track as this trainload of riders is launched out of the station. The first launch is quite a rush and you get going faster and faster as you go forwards and backwards until you get up to 70 miles per hour.
A magnet is suspended above a superconducting pellet because the induced currents on the surface of the superconductor create a magnetic field that opposes the magnet's field by Lenz's Law. The phenomenon is best described by the Meissner Effect.