As was mentioned on the Zend Developer Zone, a Dutch PHP TestFest has been announced by Stefan Koopmanschap in a recent blog entry:

(from the ZDZ translation):

We are very proud that testing guru Sebastian Bergmann will be present at the meeting! Sebastian is the man behind Unit the test framework PHPUnit, and is seen as the authority in the field of tests and quality control in the PHP community.

The event will be happening on May 10th starting at about noon and going until around 4:30 in the afternoon. You can get more details from Stefan's blog entry including a link to register for the event.