That’s not a question that is easy to ask a search engine, but Polar Rose is a search engine that claims to answer yes.
What it says it can do is recognise the faces of people and recognise other occurrences of that person on other pictures in other situations.
Say you have a picture of Charles Darwin, you can tell the search engine that this is Charles Darwin and then it will find other pictures of CH.
Now, any search engine can find (images of) Charles Darwin, provided they are tagged or captioned, or have it in its metadata. The interesting thing with Polar Rose is that the images supposedly do NOT need to have any such information. The search engine is capable of recognising similar faces and identify that it is the same person.
It is associated with a browser plugin that identifies photos with people on pages you browse. If the person is recognised and named you’ll get a red rose, if the person is unnamed it will be orange. You can then go ahead and name the person. I have not yet tested the plugin.
The project is now a small start-up company (based in Sweden). It sprung out of computer vision research at Lund’s university.
The question now is “what will we use it for”. It may well be, like with e.g. blogs, that it’s an interesting new technology, but one that we do not quite yet know what to do with.