“One of the features I find most interesting in Google calendar is the possibility to create shared calendars, but also the availability of your calendar as XML or ICAL whether it’s a private or public one. As soon as we had XML of our calendar available I was wondering why not integrating Google calendar directly into a website. For example, a community that uses the service to manage their events, or to display your future trips in your blog?”

Website: http://ajax.phpmagazine.net/2006/04/howto_integrate_google_calenda.html