Loved this look at the AWS infrastructure from James Hamilton, AWS VP and Distinguished Engineer.  (Yes, even their VPs are engineers.)  Fun entertaining and mind numbing talk with respect to the scale of their infrastructure.

http://www.youtube.com/watch?v=WBrNrI2ZsCo

"A behind the scenes look at key aspects of the AWS infrastructure deployments. Some of the true differences between a cloud infrastructure design and conventional enterprise infrastructure deployment and why the cloud fundamentally changes application deployment speed, economics, and provides more and better tools for delivering high reliability applications. Few companies can afford to have a datacenter in every region in which they serve customers or have employees. Even fewer can afford to have multiple datacenter in each region where they have a presence. Even fewer can afford to invest in custom optimized network, server, storage, monitoring, cooling, and power distribution systems and software. We'll look more closely at these systems, how they work, how they are scaled, and the advantages they bring to customers."