Cloaking device prototypes are usually either pipe dreams or poorly executed, but this experiment out of UT Dallas is incredible. Utilizing the same principle behind a mirage, Danger Room reports, the carbon nanotube plate completely vanishes at a button-press.
By heating up the water immediately around the nano plate, rays of light are bent away from the material, preventing a reflecting image from reaching an eyeball. The warped rays protect the object from visibility perfectly. It's unclear whether this approach would work from all angles, and obviously, these are laboratory conditions, not the real world, but I can imagine many a Navy engineer licking his lips at this. [IOP via Danger Room]