On the IBM developerWorks page today, there's this new tutorial dealing with reading and writing XML with the DOM functionality in PHP.

Myriad techniques are available for reading and writing XML in PHP. This article presents three methods for reading XML: using the DOM library, using the SAX parser, and using regular expressions. Writing XML using DOM and PHP text templating will also be covered.

They look at what XML is, how to read it into PHP (with examples of DOM, SAX parsers, and regular expression methods), and writing out XML. The DOM functionality that they use for the examples is the newer, PHP5-compatable methods...