The only way to truly protect your images so that no one may save them onto their own computer is to keep them off the internet. No matter what you do, as long as your image appears somewhere online, it is saveable by the user. Right-Click scripts, transparent cover images, and even expensive image encryption scripts can all be avoided. To see how, visit WebDev FAQ's.
The best way to identify an image as your own is to add a watermark in the corner.