As pointed out by his post on the PHPGeek.com blog, Jim Wynia has worked up some scripts for connecting his Google Calendar with his site that's powered by Zend Framework.

It struck me that keeping track of that stuff on Google Calendar would be a reasonably good way to centralize [a list of daily accomplishments] and make it accessible from any of the computers that I work on (Windows, Linux, Mac, etc.) without depending on software. So, I took a quick look at the PHP API for using GCal's information. It requires the Zend Framework, so this was an opportunity to install that as well.

Once he got the Zend Framework installed, he installed the PHP adapter. He talks about the configuration changes he had to make to the Calendar.php file and gives an example of it in action.