It is much easier than you can imagine. Just see the second part of tutorial

So, how would you copy the guy’s fingerprint? Let’s say he’s a stranger…

Ed,
Optical fingerprint scanners are not reliable. Optical sensor cannot distinguish fake from real. Even those that cost more than $700, like Crossmatch and are used in visa program by UK and USA government.
Matrix capacitive scanners are also not reliable. Swipe-type sensors, like Upek, LTT, Authentec, Atmel are a bit more reliable, because they need some proficiency to fake a finger they will accept.
What I am trying to say is that Biometrics has nothing to do with Security, at least in the way it is currently used.

Biometrics can offer user convenience and ease of operation, and enhance security indirectly. For example, if you must not remember your password, and if it is filled automatically after your finger recognized – you may use long and strong ones. Another example - your digital signature is released after you are recognized.
Anyway, these applications must be used with personal devices and in no way with publically available biometric terminals.

alright you debunked finger scanning, but whats the real deal with optical scans?