Well, this one is rather simple, yet pretty useful. (specially if you use wordpress)
Content scrappers are a hell of a Sc*m, or maybe not... I have thousands of visitors per month coming from content scrapper sites.
What do I do?
Well, that's pretty simple, I ALWAYS link each and every post/article of mine to my own site or to some of my other sites (related stuff, of course), which means a bunch of free links after some time, as most of these scrappers just get the entire post with everything that's in it.