Sergey Brin wrote this year's Founders Letter for Google's annual report which was released at the end of 2008, but they posted it to the Official Google blog today since today is their annual stockholders' meeting.
http://googleblog.blogspot.com/2009/05/2008-founders-letter.html

But if you look about 1/3 way down the blog, he links to a Blogoscoped post that shows the evolution of the homepage from 97-07.
http://blogoscoped.com/archive/2006-04-21-n63.html. That's pretty cool. I wonder how many times this site has been cited on Google's blogs?