Mine was down too. So I looked here to see if it was posted yet. Incredible. I've never seen Google down, but I've seen FB down many times in my life.
Facebook's front page is dynamically generated for every user. Google can essentially throw up a static page even if everything goes wrong in the backend.
Facebook has to do a lot more work to avoid the appearance of being down. Perhaps a better comparison would be Facebook versus Gmail. I've seen Gmail go down several times.