Charlie Munger was quoted at a Berkshire shareholder meeting a couple of years back saying that he thought Google had one of the widest economic moats he had ever encountered after reading In The Plex.
This inside look at their data centers is visual support to that claim. I also remember in the Columbia Business School Class presentations Glenn Greenberg citing Google's tremendous infrastructure and world class talent pool/attraction as competitive advantages. All investment pontifications aside, a look under the hood at Google is quite impressive!
Check out this Wired.com story on the data centers as well as Google's own photo gallery linked just below.
Where the Internet Lives: Google Data Center Photo Gallery