GeoHash Gem for Ruby (c) 2008 David Troy dave@roundhousetech.com Geohash is a latitude/longitude encoding system invented by Gustavo Niemeyer when writing the web service at geohash.org, and put into the public domain. Geohashes offer properties like arbitrary precision, similar prefixes for nearby positions, and the possibility of gradually removing characters from the end of the code to reduce its size (and gradually lose precision). See these resources online: http://geohash.org http://en.wikipedia.org/wiki/Geohash http://openlocation.org/geohash/geohash-js (javascript implementation and demo)