In PHPMaster.com's latest tutorial Lukas White introduces you to using the Yahoo "Placemaker" web service to geographically locate a place from a free-form text string. The results include "place details" like the type of the location, latitude, longitude and how confident they are in their match.
The challenge then is to do two things: work out what place you could be talking about, disambiguate if necessary, and then identify exactly where on Earth that is. That's what I'll show you how to do in this article; by using a freely available web service, we’ll write a simple program to ask users where they are (and ask them to clarify if necessary) before identifying their responses in concrete terms.
He shows how to make a request to the Placemaker web service, passing it a string coming from the user, to be located. The POST request contains a few pieces of data including an application ID , your desired output type and the language you're using for the input. His example code uses curl to make the request and handles it (the XML response at least) with a call to simplexml_load_string.