In this new post from the Ibuildings techPortal today Peter Verhage suggests a good way to learn all about the new features in PHP 5.3 - build your own ORM system.
Creating an ORM for PHP is not an everyday task but writing one is a good way to improve your PHP skills, especially if you use some of the additional features PHP 5.3 adds to the language. There are many excellent ORMs (Object Relational Mappings) already in existence and for a real-world project it would probably better to use one of these, but this tutorial uses the task of creating an ORM as a way to take a look at applications for some PHP 5.3 features.
He makes use of namespaces, interfaces, static variable/method handling, magic methods like "__set" and "__unset" as well as abstract classes - all features of some of the latest PHP releases (5.2+). By the end you'll have a basic ORM layer that can do all of the usual CRUD operations as well as more complicated searching and a few things those familiar with the Zend Framework are used to.