[citation][nom]alidan[/nom]give me 100$ and i could make some realistic facial appliances that would fool real people, much less a computer.[/citation]
I believe/agree with you. These systems work by taking measurements of things like the distance between your eyes, between your ears, distance from your eye corners to the bottom of your nose, etc. It then creates tables of ratios to form a sort of biometric hash of your face (obviously with fuzzy logic to account for things like wearing glasses, growing/removing facial hair, etc.). To defeat such a system, you simply need a facial appliance, as alidan suggested, that would alter these features thereby creating a false "hash" for the wearer. With practice, you could become skilled enough at applying them that they would look as good as anything produced by Hollywood. Granted, a human being might think you look a little odd (at a subconscious level, we expect faces to look a certain way and we are keenly aware of even minute deviations), but it would more than enough to defeat even billion dollar facial recognition systems.