using photos as a search medium

I am curious to know if there is a way to use google or any other search system, to find info or more pics on photos, that one can just paste onto and press enter to find similiar photos or info?
If you can type in the name of a particular subject and then use the pic search to locate more pics of it then you must be able to do it vice versa or am I just way out there?

I don’t know a whole heck of a lot about computers or the Internet, but that sounds like it’s a bit out of the realm of current technology.
Sure would be cool, though!
Just drop in a pic of a Sherman, and get back 2 million more Sherman pix!

Photo recognition software is still in the infant stages, but I think it shouldn’t be too long (a few years, anyway) until it’s a valid system. Great potential, no?