On BBC Breakfast this morning there was an article about a new material that was black and that absorbed over 99.8% of light (I can't remember it's name), but the comment was made that it's more expensive than gold.
They then went on to talk about, and show clips of, a building at the winter olympics that has been clad with this stuff, it looked wierd, and people commented that they felt quite disorientated looking at it. Must have cost a bloody fortune though if the cost comment was true.
I can imagine some interesting, and scary, applications for this stuff.