Lexus has built a hoverboard, yes, a functioning, floating board a la Back to the Future II. Teaming up with a group of scientists from IFW Dresden and evico GmbH, the team brought their expertise in magnetic levitation and created a technology that utilizes two "cryostats" that contain reservoirs which hold superconducting material that is immersed in liquid nitrogen.
Combine that with a specially constructed track and you voila! you have a hoverboard. Lexus used 200 meters of magnetic track that was brought to Barcelona, Spain and was then laid under the "hoverpark" complete ramps, rails, and even a water feature that you can glide across just like Marty McFly did when he escaped future Biff Tannen and his minions. No word yet on whether we'll ever see any commercial applications for the technology.
More info at Amazing in Motion