TinEye is a reverse image search engine, a useful tool for searching Facebook images etc.
TinEye is a reverse image search engine. You can submit an image to TinEye to find out where it came from, how it is being used, if modified versions of the image exist, or to find higher resolution versions.
TinEye is the first image search engine on the web to use image identification technology rather than keywords, metadata or watermarks. It is free to use for non-commercial searching.
TinEye regularly crawls the web for new images, and we also accept contributions of complete online image collections. To date, TinEye has indexed 1,953,157,319 images from the web to help you find what you're looking for.
Our goal with TinEye is to connect images and information and to make sure that images can be attributed to their creator. If you are managing a large image collection, get in touch to have your image collection added to TinEye. This makes it easier for the original image authors to be found.
Link: http://www.tineye.com/