abovetopsecret.com is an interesting repository of all kinds of documents, all supposedly "above top secret". Some of them are plain kooky (like this stuff about the Omega Agency or the aliens in Dulce, NM), but others seemingly offer tantalizing glimpses of the technology behind the Government's impishly named "Unacknowledged Programs".

Here, for example, is a news article from a highly respected source: the BBC. And here is an article from ats.c that might be about the same technology.