On NetTuts.com today there's a new tutorial talking about a part of PHP that can be quite powerful but isn't used too often - reflection in PHP. Using Reflection you can get information about your actual code and its elements without having to try to parse it yourself.
Reflection is generally defined as a program's ability to inspect itself and modify its logic at execution time. In less technical terms, reflection is asking an object to tell you about its properties and methods, and altering those members (even private ones). In this lesson, we'll dig into how this is accomplished, and when it might prove useful.
They provide a little context around the idea of "reflection" in programming languages and then jump right in with a few sample classes. They set up their "Nettuts", "Manager" and "Editor" classes and show how to use the ReflectionClass functionality to get their structure. The examples show how to get the class' methods, their properties and calling these methods using things like invoke and call_user_func.