It's been a sci-fi standard for generations – show the photo of a face to a machine, and it comes up with the name. Digital spies, of course, would love to use such technology to identify every face in airports. That's still far away. But for hobbyists, simple face recognition will help sort out who's who in family photos.

Google's Picasa is already offering a version of this technology. (New beards must cause problems. And forget about twins.)