One of the things I do to keep people from copying my photos is to import the photo into a photo editing program, (I use photoshop), and with a text tool I insert my company name and the copyright symbol and the year. For instance, Worldwide Decor (c) 2003. Then I set the opacity real low to where you can see the picture clearly, and just barely make out the words. Nobody will want to copy your picture then because everybody would know they stole it.

I also have the code for disabling the right click if anybody needs it. But I think putting your name on the picture is the best way to stop theives.