Swedish engineers working on infrared-"invisible tank":

The system, developed by Bae Systems and known as "Adaptiv", allows an object to blend chameleon-like into its surroundings and vanish when viewed in infra-red.

The technology is based on sheets of hexagonal 'pixels' that are able to change temperature very quickly.

On-board cameras collect images of the vehicle's background and display that infra-red image onto the vehicle panels, making it appear to vanish.

(Via Neatorama.)