Invisibility Cloak: You're Looking at It
If you're a fan of Harry Potter and/or totally rad things, you're aware of the concept of an invisibility cloak - a piece of magical or high-tech (Difference? Nope.) fabric which renders whatever is under it invisible to the human eye. Now researchers in all over the world are getting close to it. Which country will be the first to get one of Master Chief's favorite technologies.
Despite what you might think, this technology, or at least the idea of it, has been around for a few years already. And with several laboratories approaching several theories about how best to become invisible, the walk to Hogwarts has never been shorter (because you're too young to apparate).
Researchers and Carnegie Mellon have achieved the effect in the nanoparticle realm. Basically, they can make particles transparent, but that would (for now) make you very visible since the particles would be what the cloak is made out of. Until they can apply the same "particle greasing" technology to a whole human, they're at the back of the pack.
Britain seems a little closer. John Pendry of Imperial College told MSNBC
"We're very confident that at radar frequencies, these materials can be implemented on a time scale of 18 months or so,"
Sydney University is doing it, Berkely is the most recent addition. University of Pennsylvania is on board, and Tokyo, too. It actually appears to be neck-and-neck, but it is pretty clear that the kind of technology you're dreaming about won't be around for some time.
Most of the techniques use some form of "metamaterial" which basically takes the light particles from on side of it, bends them around the material itself (and you if you're under it) and spits them out the other side the way they came in. To a third party observer it looks like no bending at all went on. Kinda like this: