@toast:
http://www.google.com/support/webmasters/bin/answer.py?hl=en&answer=66359
Duplicate content generally refers to substantive blocks of content within or across domains that either completely match other content or are appreciably similar. Mostly, this is not deceptive in origin. Examples of non-malicious duplicate content could include:
* Discussion forums that can generate both regular and stripped-down pages targeted at mobile devices
* Store items shown or linked via multiple distinct URLs
* Printer-only versions of web pages
However, in some cases, content is deliberately duplicated across domains in an attempt to manipulate search engine rankings or win more traffic. Deceptive practices like this can result in a poor user experience, when a visitor sees substantially the same content repeated within a set of search results.
If you find that another site is duplicating your content by scraping (misappropriating and republishing) it, it's unlikely that this will negatively impact your site's ranking in Google search results pages. If you do spot a case that's particularly frustrating, you are welcome to file a DMCA request to claim ownership of the content and request removal of the other site from Google's index.