incrediBILL - 7:08 pm on Aug 8, 2010 (gmt 0)
The solution should be simple, something I call "Crawl-Delayed Publishing"
Publish content via a sitemap ping only to Google first, do not link it into your site or add to RSS feeds yet. Wait for Googlebot to crawl the new pages before actually linking the page to your site and adding to the RSS feed for the rest of the world to see.
At this point your page is 100% unique, absolutely first, nobody can claim ownership otherwise because you were the first to publish it worldwide.
Pretty trivial really, just keep it hidden until Googlebot fetches the page.