This may be the genealogy tool I’ve been wanting. PhotoFaceMatch, still in the development stages, can compare facial features of a person in two or more photographs. It tries to determine the likelihood that it is the same person. I don’t know yet how well it will do with faces of varying age. It would be great to have a tool that can tell you the probability of a match of your great-grandfather’s face at age twenty with another face at age sixty (which might be your great-grandfather).