Is there a way to prevent person from printing or right clicking on a picture without having to watermark it?
Watermarking is the only 'secure' method. Preventing 'right clicking' only stops newbies. If a pic is shown on your monitor, then you have it on your computer, just search the cache of your browser.
There's a plugin (I at least think I have seen one) that prevents right clicking. And there's a theme mod, that's putting a transparent gif in front of the image. So if you try to save it, print it within the browser, you'll save/ print the gif.