I have created a class to assist me in this task [ Quixml::Quick Xml and Xsl for PHP ]

I use a browser detection mechanism to determine if they support native XSLT processing, and if it's the case, I send directly the XSL style sheet with the XML to the browser.

I find this method to bring me a more organized way of designing my applications.
More portable too, as my class allows me to create "rendering sets" that can be switched on the fly, for different output medias (think mobile devices here).

I used this method of development in my last job, as an Oracle dev, where an interface was rendered to the browser that way.
I found it so elegant that I decided to move my dev process under PHP to use the same procedure.