Ben Ramsey has a reminder for those attending this year's Zend/PHP Conference & Expo (or maybe an incentive for those not yet signed up?) about the Unconference that will be happening in its own space where developers can come and present on their own topics.
When was the last time an event challenged your assumptions, and made you think? The PHP Unconference is a way to bring people who have a shared interest in PHP together. It could be just to explore interest in a common theme or it could be to do work together to accomplish a goal.
This year's chairperson is Patrick Reilly and they've posted some basic principles presenters will need to follow as well as a space on the wiki for topic suggestions or ones you'd like to present on.
You can learn more about this year's conference from the main conference website and stop by the zendcon channel on the Freenode IRC network to meet other attendees.