General -
YouTube videos:
A good general one: https://www.youtube.com/watch?v=eZTfgNIiNUA
The Czech Technincal University's Cybernetics Department and face recognition:
http://cmp.felk.cvut.cz/cmp/demos/Viden06/recognition-e.pdf
A rather un-orthodox, but reliable means of biometric identification: Knees
A good list of various types of biometric idenification techniques:
http://www.biometricsinstitute.org/pages/types-of-biometrics.html Use the link to read more about the following list:
DNA Matching
Ear
Eyes - Iris Recognition
Eyes - Retina Recognition
Face Recognition
Fingerprint Recognition
Finger Geometry Recognition
Gait
Hand Geometry Recognition
Odour
Signature Recognition
Typing Recognition
Vein Recognition
Voice / Speaker Recognition
Voice - Speaker Verification / Authentication
Voice - Speaker Identification
Another interesting one is head bobbing.
Head bobbing biometrics is one cool way of identifying people among a crowd, like at an airport. As long as the person does not suspect they are being monintored, and try to change the way the walk, the way their head bobs up and down as the walk is very specific to them.
Multi-factor authentication -
So biometrics along with other authentication is a good combination. The thing with biometric authentification is that it can be expensive to be done to a high level of accuracy, but if not the highest quality, in combination with other authentication means they can yeild good overall accuracy.