WareLogging, [PHP], [Documentation].

Given the syntactical debt PHP owes to Perl, would POD have been too much to ask for?

Probably. 

Ok, so there's nothing stopping you from doing this:

 <?php

 /*

 =head1 NAME

 stupid_thing.php - Do something stupid.

 =cut

 */

 ?>

And using the usual POD tools to extract.  But it sure is kind of ugly.