Drudge links to the article "Pentagon System Hopes to Identify Walks":

The Pentagon is developing a radar-based device that can identify people by the way they walk, for use in a new antiterrorist surveillance system.

Operating on the theory that an individual's walk is as unique as a signature, the Pentagon has financed a research project at the Georgia Institute of Technology that has been 80 to 95 percent successful in identifying people.

It contains this defensive quote from the researcher doing the study:

"We are research and development people. We think about what's possible, not what the government will do with it. That's somebody else's job. And this isn't a weapons system."