Basically, this MIT Media Lab project uses a small plastic-coated spherical magnet, called ZeroN, that can move around and be placed anywhere within its 3D block of anti-gravity space. This means that ball can be placed in any spot in the air and just stay there. This is pretty cool and is accomplished using a three-axis motor controller, while tracking motion using none other than two stock PS3 Eyecam devices, alongside a video projector. It's amazing just how many high-tech projects seem to get started using parts that are meant for gaming systems, actually.