A small extension of my previous post. Logic, geolocation within India is very much possible. Atleast I know Google can do it. The only hitch is that it doesn't work well with Wireless connections. For instance, I frequently use a Reliance Wireless modem, which is registered in K'taka but even in Bangalore, Coimbatore, Pune, Hubli it says it's a TN based IP. Ditto for Tata Docomo.