Jason Gilmore is at it again! You might remember the article he authored that appeared on Developer.com titled: "Making the most of the Google Maps API".
He has just completed a brand new Google Maps tutorial which has been posted to Developer.com titled: "Retrieving Map Location Coordinates". In this article he shows readers how to take advantage of geocoder.us and the PHP 5 SOAP extension to retrieve coordinates. Here is the tutorial.
Good luck creating all those great Google Maps mashups!