Originally Posted by deepsand

To get truly accurate results, you need to specify the Data Center (DC) for the area in question by IP Address or use a fully qualified URL (DC Name); or, use one of the available online services that will feed your query to selected DCs. One such tool is at Google Data Center Multiple IP Address SEO Research Tool .

Royal Pingdom » Map of all Google data center locations shows a global map of Google's DCs.

Wayfaring Map - Google Datacenters has an interactive map that identifies each DC location.

To get a the name of a particular DC given an IP Address, you can use ping or traceroute. Examples of fully qualified URLs (DC Names) in the US are:

py-in-f104.google.com

rn-in-f104.google.com

nf-in-f104.google.com

wr-in-f104.google.com

jc-in-f104.google.com

hk-in-f104.google.com

lm-in-f104.google.com

kr-in-f104.google.com

kc-in-f99.google.com

kc-in-f104.google.com

qb-in-f104.google.com

eh-in-f104.google.com