A nice article on Google's custom servers and datacanters. It is fascinating how they work with scale and innovate beyond current "best" practices. They do what makes sense and improve things where they can. Their scale makes every fraction of a percent a big deal.
I wonder if any of the traditional server vendors will begin to offer 12v battery options. I'm sure companies like APC don;t like to read hard numbers about per-server batteries being more efficient than external UPS's.