Free E-Book on mapping the internet

Ever wonder what the internet looks like? Well wonder no more, relief has come in the form of a 227MB pdf file, that contains the book Atlas of Cyberspace. Yours, free for the taking at this link: http://www.kitchin.org/atlas/index.html

I've just started browsing through it, but so far the early maps of the internet when it was just a 4 computer network between universities are very cool.