Google has put out a new Webmaster Help video featuring Matt Cutts talking about some things "you might not have noticed" about the company's How Search Works site.
Google launched this site a little less than a year ago. It's part of the company's Inside Search site, and includes visuals about search, a view into major search algorithms and features, a big document about guidelines for search raters, a slideshow about spam removal, graphs about spam and policies that explain when Google will remove content.
One thing he mentions is where it says how many searches Google has handled in the time that you've spent on the page. He then talks about videos that appear on the site that talk about how Google rates search quality.
He talks about different elements of the site for about ten minutes, so if you haven't spent much time perusing it, you may want to listen to what he has to say. You might find something that captures your interest.
Believe it or not, he likes the spam section the most.