Here's new software that will help you know where your images end up online. You might want to sign up for the beta of TinEye, it is a visual search engine -- it matches the "thumbprint" of images, instead of filenames.
To see how it works, check out the following:
http://tineye.com/widgets/display/
http://tineye.com/login
They've only indexed a small portion of the Internet at this time (about 500,000 sites) but I think it is growing and is probably a good search tool for artists.