New on his blog today Sameer Borate has posted a new tutorial about using the GeoNames web service to look up geographical information about your visitors (and help with targeting the experience just for them).
Geographical information integration is rapidly becoming an integral part of many websites. People use geographic data for a wide variety of applications. From location based content targeting, censoring information by geographic areas to analyzing website traffic by region. It is surprising how much free geographic information is available on the web. GeoNames is one such service.
The database is released under a Creative Commons license, so it's available to all and getting the libraries installed to use it is a single "pear install" command away. He includes code showing how to make a sample search for cities, countries and "neighbors" as well as just performing a generic search off the data. He also throws in a method for accessing the information via jQuery (an ajax call)