Dividing the world space to geographic sub-space

Question

I am trying to divide the world space to geographic sub-space from "general" to "specific" locations and without using latitude and longitude information. That is, I am trying to think about the world in someway like the following:

The most "general sub-space" > ... > The most "specific sub-space"

Example

Continent > State > Region > ... > City > Town > Address

1. What is (are) the most used "division approach(es)"?

2. What is (are) the most efficient "division approach(es)"?

Answer 1

This is a problem that everyone solves with a slight difference. IMHO, Yahoo did a great job with WOEIDs.

As far as what is the most efficient way, it seems the answer is too subjective and dependent on your application.