Actually, the AuthenTec technology Apple bought is very cool. It uses a combination of capacitive and RF tech to look at the live layers of the skin, and includes dynamic properties such as blood flow as part of the match. It doesn't use optics at all, and completely ignores the appearance of the surface layer of dead skin cells. Images of a print, residue from a previous print, or even a dead finger, won't fool it.
7/27/13 at 5:53pm