Scientists managed to create a device that is able to cloak a small copper cylinder from microwaves during testing:
The cloak of invisibility only works in two dimensions and only on microwaves. The research conducted by Professor Sir John Pendry of Imperial College of London while working at Duke University involved deflecting the microwaves around the copper cylinder while being able to restore them once they reached the other side of the object. The little amount of distortion made it look like there was nothing there at all. The research team also used microwaves to try and detect the cloaked copper cylinder with little success.
Currently it only works in 2 dimensions but the team has started working on a new device that will work in 3 dimensions. More details at DailyTech.