There are loads of ways people try, but loads of ways people can just grab the text...
At the end of the day, if they want it, and its worth something to em, then they can resort to pen and paper...
Saving text is images is a fairly secure way, as to get the image back into text you would have to do OCR on it...
Another way, is FLASH, again, pretty hard and lenghy to extract text if the text commands are used right, if they are not, then you can copy and paste the same...
You can password, and protect PDFS, but you could screen dump em, and then do OCR...
I noticed JAVA script was said, you can encrypt the html source, and then add
js to block the left mouse click, but then the user could disable
JS in there browser, or even use CTRL-C to copy...
Make sure Google index your copy first, and then you can search google for specific quotes in the text and see if anyone has coppied it. If it was indexed in Google first, before the other website then you would have a stronger case to make em remove it, or register the text with the many copyright websites.
If it was me, i would make the website in flash, and just use flash to protect the text, that way you can make it dynamic, have no special readers to download and dont have to worry about
js compatibility in web-browsers.