The Department of Homeland Security, keeping our best interest at heart as per usual, is working on new technology which will act as an artificial nose, smelling airport passengers as they go through security.  If all goes as planned, the noses will be able to report to security workers not only the passengers' emotions - fear, anger, and other emotions all produce their own unique scents - but also, in some cases, their identities:

The technology builds on recent breakthroughs in finding human scent-prints which, many researchers believe, may be as unique to individuals as fingerprints...Homeland Security wants a device that automatically compares odours with scents collected from crime scenes and held in a “smell bank” which, like DNA or fingerprints, could be used in court.

The devices will also be programmed to distinguish and ignore common perfumes, which could otherwise interefere with identification.  I'm thinking purchasing some obscure off-brand perfumes and applying them heavily whenever I go to the airport is going to start looking like a good idea...