Sorry this took so long, but here you can download the PDF or the much better Keynote version of my slides.

He also has an embedded Slideshare player on the post of you want to check out the presentation without the download.

While working on a project I realized one particular solution was a pretty good way to demonstrate the decorator design pattern together with some of PHP5's features, including abstract classes, interfaces, type hinting, the final keyword and the visibility of properties and methods. This article is intended for those of you who, like myself, are moving from object-oriented programming, including some use of design patterns, in PHP4, to the more complete object model of PHP5.

He sets up a scenario about the development of an online pizza ordering system to show how to "decorate" a pizza with each of the toppings on a list (instead of having to list out every pizza in every possible topping combination). Of course, all of the code is included and explained so you understand exactly what's happening. Finally, there's a demonstration of its usage - a simple call that grabs the stock level/name/cost of each of the items in stock (pizza combinations).