Reverse image search engine
Does anyone know of a search engine that allows you to upload an image and then find similar images on the web?
"What is TinEye?"
TinEye is the first image search engine on the web to use image identification technology. Given an image to search for, TinEye tells you where and how that image appears all over the web—even if it has been modified.
this is a small showcase of what results you might get when searching :
Not possible to upload an image though, but if it's somewhere online, chances are they already indexed it ;-)