Hi Sal,
Thanks a lot for your suggestion. The problem is, there are so many other ways to steal images that preventing right clicks is actually sometimes more of an annoyance for legitimate users than a deterrence for thieves, since it prevents all the other userful options that right click provides.
Even if right clicks are disabled, thieves could simply take a screenshot of the page to steal the image, or view the source code to obtain the address to the image file.
If you'd like to discuss this, feel free to email me at michael@photoblog.com
--Michael