given a list of words, i need every unique combination where the list is in alphabetical order.

Sorting Code Challenge.php

<?php
function order_list($words, &$return = null)
{
	if(!$return) $return = array();
	
	sort($words);
	
	$string = implode(', ', $words);
	if(!empty($string) && !in_array($string, $return)) $return[] = $string;
	
	foreach($words as $key=>$word)
	{
		$temp = $words;
		unset($temp[$key]);
		sort($temp);
		$string = implode(', ', $temp);
		if(!empty($string) && !in_array($string, $return)) $return[] = $string;
		
		if(sizeof($temp) > 0) order_list($temp, $return);
	}
}

order_list(array('apple', 'zebra', 'cat', 'bear'), $result);
if(!empty($result) && is_array($result))
{
	echo "--------\n";
	echo implode("\n", $result);
	echo "\n--------\n";
}

echo "\nDone.\n";
?>

Moved this from a private gist to a public.

Another solution: https://gist.github.com/764121