If you've been anxiously awaiting part two of this series then your wait is over. Here's a short introduction to the section part of this series written by the author of the book, Dagfinn Reiersol. I had the privilege of meeting Dagfinn at phpuk last week. Below the introduction is the link I know you've been waiting for.

The new PDF they link to focus on two different patterns - the Decorator (a wrapper class) pattern and the Null Object (an object that works like the others but does nothing behind the scenes) pattern.