said by justin:the only biometric scan that I'm impressed with this the one in the incredibles:
Hand Scanner.
Iris Scanner.
"Edna. Mode." (said in purposefully flat voice)
Then there is a camera (IR?) that identified an additional visitor - judging by the machine gun that springs from the ceiling.
".. and guest".
This is smart because if she is being forced at gunpoint to surrender all her biometrics, the bad guy then has to deal with the weapon pointing at his head as well.
There are some secure facilities that use a slightly different arrangement. It's a self contained plexiglass chamber, and you surrender your retina pattern, while the floor plate determines exact weight of things present on the floor. Combined you gain access. Yes, for those who eat lots or are on diets there are problems, and for equipment, I think there needs to be some kind of override, I"m not sure.