John Pendry and his colleagues at Imperial College London have calculated that special materials engineered to have abnormal optical properties, known as metamaterials, could make light pass around an object so it appears as if it were not there at all.

Other designs for invisibility cloaks have been contemplated in the past.  One idea was to calculate exactly how an object scatters light and design a surrounding material to exactly cancel this out.  But that type of cloaking device could not be used for more than one object.

Watch out for the Klingon battleships or maybe even a Ford Mustang with this option!