For info on Digimarc, the one that is in Photoshop, go to: http://www.digimarc.com/watermark/about/ There are several levels of expense with this service, but it is the most commonly used. The ultimate level here is a usage/web search for your watermark with reporting feature. A concern for many of us fer'shure; I'm trying small file sizes relative to print size, heavy compression helps, but isn't a firm solution, but it is free. One artist I know has a password protected web gallery, and only gives it to brick & mortar galleries, or previous/possible clients [that he's meant in fairs or exhibitions]. Do you make a living off of your artwork like some of us? If so the web has some real obvious benefits, but some terrible drawbacks as we all know. Before I put my art galleries up with my commercial site, i contacted a couple of dozen on-the-web artists about the sales that they generated of the art that was specifically posted. Minimal to none was the reply, but many commissions and/or arrangements to view at a real gallery occured often enough that the risk & expense seemed worth while. Bonne chance !