Sebastian Bergmann has posted another update about the upcoming PHPUnit 3 project, this time concrening the improved skeleton generator that's been put in place.
PHPUnit can help you write your tests by analyzing the code of an existing class and generating a skeleton test-case class for it. With PHPUnit 3 this feature will be more powerful as it now supports @test annotations in the class source.
To illustrate the point, he gives a bit of code for a calculator class with a single add() method. When the skeleton generator gets its hands on it though, it spits back out a complete testing suite with predefined functions ready for your assertions (and completely valid, even without them).