Diving even further into the world of design patterns, DevShed has posted this new tutorial looking at the Memento pattern - useful for (in their example) carrying objects from page to page.

Don't you worry about it for the moment, because in this two-part series, I'm going to demonstrate with numerous code samples how to apply the memento pattern so that it can be used within your own PHP applications with only minor problems.

They start with the simplest example of the pattern, working with arrays - get, set, etc. On top of that, they build a "caretaker" class that

will be the one holding the state of the object from the other class. Finally, they tie them both together to create a simple model of a caretaker that stores and remembers how the object inside is formatted.