Sebastian Bergmann has posted some details about
an update that's been made to the test runner for the PHPUnit (3.3) unit testing suite - an allowance for directories instead of just files on the command line.
Given a directory, the test runner will recursively scan the directory for *Test.php files, build a test suite out of the *Test classes, and run it.
PHPUnit is framework that makes writing tests for your code easy and also includes functionality to run the tests and analyze their results.
Sebastian Bergmann's Blog: Test Runner Improvement in PHPUnit 3.3 - Read More... 
