Google Maps: conversion adresse postale -> (latitude,longitude)

Mise à jour:

voir le site www.locoos.com qui fait cela pour la France

Billet Original
(via P. Lenssen)

Le couple de coordonnées (latitude,longitude) est la manière de positionner un objet (cf mes multiples exemples ou Google Maps Mania) sur une carte Google Maps.

John Resig détaille la méthode précise pour transformer une adresse posatle vers ces coordonnées via le service Geocoder basé sur le informations fournies par le bureau fédéral américain du recensement.

C'est malheureusement limité à USA & Canada: quelqu'un peut-il me poster en commentaire un service équivalent pour L'Europe en général ou France, Allemagne et Suisse en particulier?

PS: Comment ça marche?
(de http://geocoder.us/)

How does it work?
The US Census Bureau provides location data for nearly every street and highway in the US in the form of the TIGER/Line data set, which runs to over 24 gigabytes uncompressed. Geo::Coder::US condenses the 2004 TIGER/Line data set down to a 750 megabyte BerkeleyDB database. A given address or intersection is parsed into its components, and the matching address range is searched for in the database. The address is then interpolated between the endpoints of the matching address range to estimate its latitude and longitude. For urban addresses, the coordinates given by Geo::Coder::US can be within 10 or 15 meters of the actual location -- which is well within the range of typical GPS accuracy!

Is it really free?
You bet it is! Commercial US geocoding services can charge up to $1 per lookup, but the TIGER/Line data on which their geocoders (and ours) are based is in the public domain. The Geo::Coder::US suite is made available free for download under either the GPL v2 or the Perl Artistic License. All data from the free services on the geocoder.us website are provided under a NonCommercial-ShareAlike license, which means you can use anything you get from us for any non-commercial purpose, so long as you give us proper credit and extend the same courtesy to others.