Reuters Labs, the laboratory of the news agency Reuters, automatically recognises people in video with advanced pattern recognition software. If you search for George Bush(you get a choice of two people with the same name), George Clooneyof George Harrison you are very quickly presented with a list of the videos in which those people appear (via dc, Dutch).
Sounds advanced, but soon we'll be able to walk down the street, point our camera at our surroundings and use face recognition (and other characteristics such as the 'walk') to see who is walking past us. We won't need to tag any more photos or videos because it will be done automatically. The online identity and the real identity will meld completely. It will have an enormous impact on society. For example, in maintaining public order or restricting access to offices. But you could never again walk straight past a friend who you hadn't seen for 30 years. Your social coaching brand will know exactly who it is.