On PHPBuilder.com there's a new tutorial showing how to use the Dice dependency injection container to manage dependencies in your application.
Dice is a Dependency Injection Container for PHP. It allows you to very quickly and simply use Dependency Injection techniques in your code with very minimal effort on your end.
The article talks some about the features of the Dice DIC and shares a simple introduction to its use in a more practical example. It uses constructor injection and type hinting to automatically handle the injections based on its current set of object references.
With Dice you don't have to worry about how the User accesses the Session object, you add it as a constructor parameter and it Just works. You don't need to reconfigure the container, you don't need to do anything at all. You just alter the constructor definition and everything is done for you.