Iphoto has a neat facial recognition feature called "faces". The faces feature searches all the pictures and detects the faces. You assign a name to a detected face. Once you've assigned names to a few faces, iPhoto will learn from your input and try to put names to faces on it's own. Going to the faces pane, you get a corkboard with entries for every person you've identified so far. Double clicking on a person will take you to two areas. The top includes all the photos of the person you've identified and beneath a gray bar are other people iPhoto suspects may be the same person. It's interesting to see what iPhoto guesses. Bicycle wheels and pizzas are two of the more unusual guesses, but for the most part it guesses very similar looking people. So I identified the woman on the left as Emele Kaaukai Wright and iPhoto guessed the woman on the right as Emele, along with several other people. The one on the right is from a photo of a group of hula dancers. I'm guessing, but I'd say around 1870's? The one on the left, she looks to be about 10 yrs older, more or less.