Doing away with a phone (or a card or a chip in your head) and just going with biometrics is a different issue. Biometric identification is a much harder problem and is fraught with difficulties. It can work very well with limited populations, which is why it is being installed in airports all over the place. I rather like the system going in to Chinese airports where when you walk up to one of the screens displaying flight information it switches to displaying your flight only. Very helpful. And earlier this year at KnowID in Las Vegas I saw a super presentation from US Customs and Border Control talking about the specific use of biometrics in airports as an interesting example of how to use biometric technologies for security but at the same time deliver convenience into the mass market. The investments made in biometrics to allow paperless travel have obvious benefits in terms of security but, as we have found in our other work about the cross-sector exploitation of digital identit...