An example of how to use the class defined here: https://gist.github.com/Tarendai/6089867

helloworld.php

<?php

require_once( 'custom_page.php' );

class Hello_World_Page extends Tomjn_Custom_Page {
	public function render_page() {
		echo 'hello world!';
	}
}

$helloworld = new Hello_World_Page( array(
	'url'		=> 'helloworld',
	'pagename'	=> 'helloworld'
));