Chris Hartjes, a big proponent of testing (unit and otherwise) in the PHP community has put together a screencast to show just how easy it can be to get started with TDD (test-driven development) in PHP.

I want to talk about test driven development and show you in five minutes how to set up.

His example uses a common problem - the FizzBuzz test - and shows how to write a simple test to check the output of his "process()" method that it matches his expected results. It's a simple example, but a great (realtime) primer to how the TDD process works.