Skeletal Identification
Bruce Schneier noted a story today over at his blog about a new Skeletal Identification System being developed at Wright State. Of course this is just another biometric detection system, but one that would be pretty tough to disguise.
Xrays and backscatters? Bruce Schneier needs none of these things to identify you by your skeleton. Bruce Schneier simply removes your skeleton from your body and gives it a once-over.
(apologies to schneierfacts.com)