Re: Getting it working is the first step
The problem is everything is useless for authentication when you are dealing with communities bigger than the local. Its an age old problem of verification. How do I know you are the official you if I don't know you in the first place. Answer: I don't. I trust what I am shown and that can be spoofed, hacked, stolen, borrowed. So I get a positive ID from a retina scan which confirms your identification an authentication database. But hang on that authentication database is, er, a database, filled with data about people where the operators of that database are in the same position and also have no local community knowledge.
Of course there is certain data we will *tend* to treat as sufficient, but it is never wholly and completely sufficient. With all technologies its a matter of managing risk.
Fingerprint scanners are higher on the scale of risk than the super doesn't-yet-exist-in-practical-form technology we want, but they remain one hell of a lot better than a four digit pin entered almost daily with people being able to see over your shoulder and in the presence of "security" camera's trained on the checkout till. Yet, for that, even the four digit pin is useful and better than no pin.