On the NetTuts.com (Plus) site there's a new tutorial focusing on aspect-oriented programming in PHP, a shift from the usual methods of development with the goal of "crosscutting" your classes/objects by weaving in extra functionality. Their examples of this method use the FLOW3 framework.

All modern frameworks (including FLOW3) push a lot of patterns into the software stack that do a great job at separating the concerns of your business logic; among them the famous MVC that is separating your logic into different layers. However, an application is not only built on business logic alone. As it grows, you may want to implement additional services, features, plugins or plugins of plugins. You surely don’t want this stuff in your business logic! But what are your options?

For their example, they show how to implement a logger across your classes, taking it out of the actual code and implementing it in an aspect (at the "pointcut") by "weaving" it into a DocBlock comment with special annotations. They help you get the FLOW3 framework set up and show you how to "kickstart" a new project and work with its controllers and resources. They show you how to implement the Logging aspect and how to define it in your code (and where it caches the requests).