Pentagon sniffs for a sniffer machine DC Sniffer dogs can detect people by their odor, but the Pentagon wants to build a machine to do the same thing:  'A £2 million fund has been earmarked for the weird science project to produce a machine to  identify people by their genetically produced odor. Some scientists say it can't be done because people change in odor all the time (due to diet, clothing, environment and health conditions.) 'It would be like trying to detect an individual's fingerprints through a pair of gloves...' [Ananova.com] (okay... so smart terrorists will take to smearing themselves with  smelly camouflages -- garlic, dog poop... whatever-- and it won't cost them millions to fake out such a machine.) Related: Army research on odor detection - (Adobe pdf file)