Password not accepted: are biometric checks the answer?

I’m old enough to remember a life in which you could confidently expect your skill for guessing passwords to be redundant by about the age of nine. That was when your mate down the road finally overcame his love of spy games and his obsessive desire not to allow you past his front door or into his garden shed without you first establishing his favourite crisp flavour. Unfortunately, however, it seems that mate, who subsequently spent his lunch hours in the school’s windowless computer room, up to his knees in punch cards, has long since taken over the world.