Hi all,
I found this thread in searching for a possible solution to this problem and
here are offered some ways to solve this.
I like placing the photo as background the most, as explained
here. The reason is that I don't like watermarking and the javascript option will only filter out the users, who don't know how to turn off their javascript. But placing the image as background is so nice, because even the Opera users (tools -> advanced -> blocked content) can't block the image from showing (that's good if you have commercial banners, which you want to always show).
So thats the option I favor, and only small percent of the user know how to get the image from the browser cache. If you find any other ways, please share.