packing. In this case, those body-scanning machines we've known about for some time are being installed in 10 airports. They are already being used in Los Angeles, Baltimore, Denver, Albuquerque, and New York's JFK. Later this month, the TSA will add the bum-looking devices to major airports in Dallas, Detroit, Las Vegas, and Miami. By bouncing millimeter waves off passengers, the scanners produce a black-and-white image that's detailed enough to see the sweat on someone's back (among other things). The program is aimed at detecting objects such as plastic and ceramic weapons that aren't normally picked up by traditional methods. The technology does have a couple drawbacks, however: it can't see through plastic or rubber materials that resemble skin. Keep that in mind the next time you wear vinyl pants on your next trip to Mars, kids.