No right click scripts encourage theft as does anything else you do client side in the web page that supposedly provides "protection".
The two most effective ways to protect images are:
1. lower the resolution as far as possible and then embed a watermark in the image itself.
2. Place it as a background behind a transparent GIF image. Most of those who right click and save will not discover until a lot later that the image they got wasn't what they thought and many will not bother to come back.
To protect text you need to abandon HTML completely and use a PDF instead. You can then turn off the ability to copy the text (and other content) out of the PDF. Of course you can't prevent them just copying the entire PDF.
Neither of these approaches prevents someone taking a screen print to get the content.
Using File/SaveAs from the browser saves a complete copy of all the source files for the page to that person's computer where they can pull out whatever they want. With Netscape 7 that option even converts any obfuscated content back into plain text.
Whatever technical things you impose mean that you automatically block anyone without the right technology from being able to access the page at all. Those completely blocked will be a far greater number than the thieves you'd get without the blocks in place. The number of thieves with the blocks in place would also be higher due to those who would take your content just to prove how ineffective your block is at stopping them.
Basically anything visible in the web page is already on their computer and technically they can do with it what they like.
You are best off relying on copyright etc for protection as those are the only ways that work.