This site is very cool. It zooms almost every village of India. I was very excited, happy ( and :-( also) to look at this. And, this allows you to mark the places also. Hats off to the creator.... I came to know about this from my colleague.
I just have a doubt - what is the backend database used for these type of sites? how the mapping will be there from this database to the one that we view on browser? I just have a very high level answer for this - Spatial Database