Good software to find duplicate/matching images: Visual Similarity Duplicate Image Finder

I often need to determine if a given image is one of mine. This can be a very time-consuming task if the image has been stripped of its original file name and embedded metadata, as is often the case for images posted on blogs and social media sites.

I found a good solution in Visual Similarity Duplicate Image Finder:
http://www.mindgems.com/products/VS-Duplicate-Image-Finder/VSDIF-About.htm

As the name implies, this application searches for duplicate or similar images not by file name or metadata, but by visual similarity. It's like Google Image Search, but running on your own desktop, searching your own files.

I've been quite pleased by its performance, and it's very inexpensive.