Recently, I had success looking up an image using TinEye, a reverse image search engine. A client sent me an image asking about using it on their Web site. This is always a concern for me, since most better photos and images are under copyright, and I try to be careful.
But with a reverse search engine, you upload a photo, and the engine tries to identify it for you. In this case, we were able to determine where the image came from and how to get the needed copyright clearance. Not bad for a few minutes’ work.