InternetNews.com reports that a9 (an Amazon subsidiary) hopes to have some its technology patented. The U.S. Patent and Trademark Office recently published a patent application from a9 titled: Server architecture and methods for persistently storing and serving event data. The article mentions that, "the patent application discloses what is likely already Amazon.com's de facto search architecture, both for A9 and the e-commerce site."
More in the article: A9 Search Looks to Patent Its Shtick. If you would like to review a9's patent app, it's available here. More patents? In November, SearchDay published a compilation. Here's a blog post that lists several more.