Zend has a new tutorial posted today with a look at Service Data Objects for PHP - what they are, how they're used, and what you can do with them.

Service Data Objects (SDOs) have been around in the Java technology world since November 2003. They are designed as a means of simplifying and unifying working with heterogeneous data sources.

In February 2005, IBM and Zend announced a strategic partnership to collaborate on the development and support of the PHP environment. One aspect of this collaboration has been the definition and implementation of SDOs for PHP. This article gives an overview of SDOs and the motivations for using them in the PHP environment. A simple contact management scenario is used to illustrate key concepts.

They start off by explaining the concept of SDOs, thankfully with diagrams to show how they all fit in with the flow of data. From there, they get into the "why" behind it all - why choose SDOs? They give tons of examples and tons of code to help you understand how these handy little objects can be useful to just about anyone out there. And, the best part is, since working with SDOs is mainly just a concept/way of coding your app, you don't have to compile or link any other external libraries to get started...