Even before Harry Potter learn his art of invisibility, we were, well, researching in this particular field. Evidents show scientists, spending alot of their time and work bringing the Harry Potter's cloak invisibility skills from movie to reality.

Japanese Cloak
The optical-camouflage technology, which has been developed by scientists at the University of Tokyo, has made the invisibility cloak a reality.
First, the person who wants to be invisible (let’s call her Person A) dons a garment that resembles a hooded raincoat. The garment is made of a special material that we’ll examine more closely in a moment. Next, an observer (Person B) stands before Person A at a specific location. At that location, instead of seeing Person A wearing a hooded raincoat, Person B sees right through the cloak, making Person A appear to be invisible.

The UC Berkley scientist team has made a major development towards creating a cloak that is 100% invisible. The team, led by scientist Xiang Zhang, has developed a prototype material called metamaterials, which is a composite of materials like ceramic, Teflon and fiber. This material scatters visible light, with the goal of bending the light rays around the covered objects. This firstly hides the object being covered, and secondly eradicates any forms of shadows, making the object seem truly invisible. This is a major breakthrough because past experiments only test small 2D objects. This one takes it to the next level by cloaking larger 3D objects.

From my point of view, the government really has something here they could use for future missions. It could be use for both good, and unfortunately for bad purposes. On the good side, the army could now use technology like this to carry out high level undercover reconnaissance mission in enemy territories. From the bad side though, letting this slip into the wrong hands could prove to be a major security threat to the lives of future innocent citizens. Who knows, someone could even be Superman for a night or two. ( http://www.gizmowatch.com/entry/us-scientists-step-closer-towards-the-100-invisibility-cloak)

source