What I want from Google

I've decide that the new feature I want from Google is a comparetive image search. I know the idea of searching without words is something which we haven't tried before but I think it could be useful in a variety of ways.
First though, the technology is possible. Police use facial recognition software and I have seen programs which compare how close to faces are to each other. Since the human face is far more complex than most other images we might look up those should be possible and Google already has image search.
So to why we might want it. There are many reason. Artists would be the most obvious to me. They would be able to put their own pictures into a search to see if anyone else is using their art.
It would also be fun to be able to see other pictures of places or things without trying to play the keyword guessing game, especially on places that aren't as well known.
Beyond simply finding things you already have though, if it was done well I could find art which was similar to something i like. Perhaps in the same style, or by the same artist. I might even be able to look for parts of a picture so I could take the signature from a picture and find others with the same signature.
Those are all just off the top of my head. I'm certain that once Google makes the technology people will find more uses for it, and I'm willing to let Google use this idea completely free of charge.