Google Geocoding Web Service
Google have today announced a new Geocoding Web Service. Geocoding is the process of converting postal addresses into geographic coordinates (latitude and longitude), so that you can place markers on a Google Maps mashup.
The new geocoding service enables the precaching of geocoded results so that developers can cache the results on a server, and serve the locations to their Google Maps mashups. This ensures that the map does not need to geocode the address of a property every time it is viewed by a user.
Developers do not require a Maps API key to use the Geocoding Web Service. 2,500 requests may be sent to the Geocoding Web Service per day from a single IP address. The Geocoding Web Service can provide output in both XML and JSON.
Via: Google Geo Developers Blog