Concept of the Day: geohashing , or a method for classifying geographic locations (based on latitude-longitude inputs) from random data . This is used extensively in the context of Google Maps and other mobile applications 
Using the geohashing algorithm to find a location in San Francisco, USA. Courtesy .
 picture above is the schematic for a geohashing algorithm.
 special thanks to Randall Munroe and his brilliant xkcd comic series.
 for more information, please see the following reference: Niccolai, M. and Slatkin, B. 24 hours in SF: A Geolocation App. Google Developers App, February 04, 2009. See also a Stack Overflow discussion thread on geohashing.