I took a deep interest in php based CMS and I was hoping to build a web 2.0 site. My search led me to Joomla, a php based CMS. My earlier experience to CMS was with 'PostNuke', another PHP based CMS and quite mature with a lot of features. What PostNuke didn't have or I didn't see was that the look and feel was not that good. Joomla comes with a lot of cool templates to make your site look like a web 2.0 site and giving you the benefits of a CMS at the same time. Joomla was so good that I got quite involved in it and started developing components, templates and such. For an example of a component that I developed (in fact it is an enhancement of an already existing component) you can visit http://www.omkaragifts.info/joomla/download.php
The component is a EventList component that allows you to add upcoming Events to your site. The problem with the current EventList component was that the venue of the event had to be added first by the site administrator before an event can be added. I wanted a way where users could add events themselves. Also there was no way to feature the events and there was a chance good events would be missed in the crowd. So I added a mechanism to feature events at the top of other events. As always, the component is free and open source and is available at the above link. There's also some templates that I developed that I have made available. Though not free, they are nominally priced and available at the above link.