Originally Posted by deepsand

Each and every Google Data Center can be directly queried via its IP Addresses.

For a an overview of the locations of the current 36 DCs, see Royal Pingdom » Map of all Google data center locations .

For location specific information, see Wayfaring Map - Google Datacenters .

Note that there is but a single DC, numbered 20 on the referenced maps, in Canada, that being in Toronto.

To view rankings across multiple DCs simultaneously, try Google Data Center Multiple IP Address SEO Research Tool .

Additional info. & tools can be found at google data centers - Google Search .

You can separately query any given DC by going directly to one of its IP Addresses via your browser's Address Bar, rather than to Google.ext .