Just be reading that new software is being developed to find images and faces on the net, not just find them but actually search for them. There is already software that 'tags' people and items such as EyeALike
I think as this software develops it will be a great tool for genealogists. Eventually all those old photos that have no name can be linked to photos that do have a name that are posted by people with common interests as the software will 'recognise' them without us having to trawl through hundreds of pages looking for a nameless picture..
I collect old porcelain (sometimes) and usually there is a hallmark or makers mark...usually a symbol of some description and it's a real pain searching for something that does't have a name - just like some old photos. Just think what this sort of software could do if it could actually recognise an image from something you've uploaded yourself....such as an old photo!
I don't know about you but I can't wait!