There is an article on Google's IT strategy on InformationWeek. My favourite quote -
How often does this get forgotten, especially when we gain lots of business knowledge? Our ways are unique - that is not inherently a bad thing.There's a lesson in Google's IT philosophy for other companies: Shun the herding instinct that leads toward the same systems and software everyone else is using. There may well be competitive advantages in doing things your own way.
And another one,
"Our culture is pretty deeply embedded in many of our processes," he says. "So what we don't want to do is buy a tool, which by extension changes the cultural aspects of the way we do things."