I downloaded Ubuntu ISO and done a clean install.Upon booting it shows everything in my native language,Malayalam(language for Kerala state, India).I really wondered thinking how it happened.During installation I selected English as my default language.But how it knows I am from Kerala? Ubuntu is funny!!! I love it!
If you have an internet connection during install:
For me this results in ...
If you do no have one it will not show any default settings.
Not sure but if there is already a Ubuntu installed I would expect it to fetch those settings from the current installation too (ie. /etc/localtime) if there is not internet connection (not sure but seems logical to me ;) )
Your IP reveals instantly your location. The same applies for google, if you type google.com it will redirect you to your country's google page, unless you've clicked to 'Go to google.com in English'.
So I suspect this is how it's done.