Just a quick note. Today I found great article about Google on the New York Times. It gives some light on how Google's engineers work to improve their search algorithm. All SEO gurus should read it. ;) Here is small quote from the article:

Google recently allowed a reporter from The New York Times to spend a day with Mr. Singhal and others in the search-quality team, observing some internal meetings and talking to several top engineers. There were many questions that Google wouldn't answer. But the engineers still explained more than they ever have before in the news media about how their search system works.

Continue reading on the NY times...