Researchers led by Xiang Zhang at the University of California Berkeley have been working on invisibility for quite some time. Their approach is made possible by "metamaterials," composed primarily of "ceramic, Teflon, and fiber composite." Instead of absorbing or diffracting light, metamaterials redirect light around them, causing a perceived invisibility effect. [Quick Physics Lesson: If light doesn't bounce off an object and back into your eyes, you can't see it...hence invisibility.]
Scientists have so far only been able to cloak two-dimensional objects from view. Back in October Igor Smolyaninov's team at the University of Maryland was able to obscure small objects (just 10μm across) in two planes of vision. Zhang's new development is able to cloak objects in three dimensions. This is a momentous stepping stone to a day when we may have true stealth technologies.
Personally I'm keeping a fire extinguisher handy in case I feel like I might not be alone in the room.