While it only works on night scenarios, BAE's Adaptiv technology holy-fuck-Batman demonstration has left me dumbfounded. It can make a tank, helicopter or a battleship fully invisible at night. Or disguise them as any other vehicle.
This is how it works: 360-degree cameras are mounted onto the vehicle, which capture its surroundings in real time. This visual and temperature information is processed by the Adaptiv computer, which creates a solution that is shown on a skin attached to the vehicle's hull or ballistic armor plates.
The skin is made of hexagonal thermal tiles that effectively act as pixels. They vary their temperature like a display, instantly making the object invisible under infrared surveillance. In addition to total invisibility, the computer can also mimic other objects, effectively disguising something as huge as tank into a small car or any other object, manmade or natural.
The Adaptiv skin's tiles use very low power levels, so they can be used even when the vehicle is in sleep mode. Not only that, but the tiles themselves can act as armor and can be individually replaced in case one of the pixels gets damaged in battle. BAE says that they can also be used on fixed installations.