New : Try the demo on a map with the leaflet plugin
The worldwide reverse geocoding webservice is totally FREE and allow to find an address or a street for a given GPS coordinate in 243 countries, via a REST webservice. Gisgraphy also offers Premium hosted services and consulting.
It uses (free) data from OpenstreetMap that are imported into a local database.
Gisgraphy doesn't use Google Maps geocoder, it do it by itself..
You can see an example of use bellow. You can find documentation on how to use the XML API of the webservice and see how to download and install Gisgraphy.