This works really well. For some cool examples, check out http://tineye.com/cool_searches http://tineye.com/cool_searches Also, I recommend that you click the

This works really well. For some cool examples, check out http://tineye.com/cool_searches http://tineye.com/cool_searches Also, I recommend that you click the "compare images link" under each result image after you perform a search, to see which part it matched. I've used tineye several times, and it's found the sources of heavily photoshopped images before. They've done a great job.