Though we know for sure Microsoft has a data center in Quincy, Washington and is building one San Antonio, Texas, Manos also says that Microsoft has other data centers all over the world, though "we usually don't go into where they are."
These things are also massive, and not just the size of a house massive. The Quincy data center comes out to more than 470,000 square feet, in other words a bit larger than eight football fields put together, or about 11 acres. They draw so much power, "on the order of 10s of megawatts per facility," that one of the 31 factors Microsoft considers in building them is the local capacity and price of energy.
I wonder how they compare to Google and Yahoo's data centers, or Salesforce.com's?