Two teams (one at Berkeley and one at Imperial College London / Duke University) have developed "invisibility cloak" materials or metamaterials.
[The Berkeley] material is the first made in three dimensions to show a so-called "negative refractive index".All materials found in nature have a positive refractive index, a measure of how much electromagnetic waves are bent when moving from one medium to another, but in these materials the light is bent the 'wrong' way as it passes through, which enables it to work, in theory at least, as a cloak.
"Natural materials do not respond to the magnetic field of light, but the metamaterial we created here does," said Dr Valentine. "It is the first bulk material that can be described as having optical magnetism, so both the electrical and magnetic fields in a light wave move backward in the material."
This post at ars technica actually describes metamaterials and some of the implications of the research released today. A little math, physics and Hollywood ... what's not to like about this story?