So yes, I use iPhoto to manage my sprawling library of digital images.
iPhoto has a facial recognition feature, which–it is claimed–can automatically recognize faces and build an internal database, so you can (for instance) tell it “Show me a picture of Mom” and it’ll pull up all the photos that have her in them.
I don’t use this feature, though it’s on by default, always searching for faces even though I don’t identify any or give it any names. And sometimes, it seems to have a very…Pablo Picasso sensibility when it comes to recognizing faces. If this is the state of the art, it’s hard to wonder why the TSA has yanked all the automatic facial recognition scanners from the airports it was trialling them in: