Geoff also has some tarballs available that let you test a very simple PHP library (functions.inc) with Apache-Test, Simple-Test, PHPUnit, and phpt: http://people.apache.org/~geoff/power-php-testing
A PDF of our slides is now available: Power PHP Testing (PDF).
He also gives some other resources for finding out more about Apache/PHP testing as well as a brief mention of TAP (Test Anything Protocol)...
