You do know that stopping right-clicking is only the first, most immediate way of getting your content...and if someone really wants it, they can get it, right?
But, like prissed said, if someone wants some of your content, there are a number of ways to go about getting it. Besides, it's been my experience that disabling right click only acts to either annoy visitors and/or drive them away from your site.... or worse!
If your content is really sensitive, you might want to consider putting it in protected directories instead.