Like Ruby's to_sentance, this function returns a list separated by commas. Last item will be proceeded by "and". Example: prettyList(('a', 'b')) returns "a and b", prettyList(('a', 'b', 'c')) returns "a, b, and c". Alternate version with option array instead of individual params.

prettyList()

<?php

function prettyList($list)
{
	$listCount = sizeOf($list);
	if($listCount == 1) {
		$listString = $list[0];
	} 

	if($listCount == 2) {
		$listString = implode(' and ', $list);
	} 

	if($listCount > 2) {
		$lastItem = array_pop($list);
		$listString = implode(', ', $list);
		$listString .= ', and ' . $lastItem;
	}
	
	return $listString;
}

// Even better - from Titan (Miles Johnson)
public static function listing($items, $glue = ' and ', $sep = ', ') 
{
	if (is_array($items)) {
        	$lastItem = array_pop($items);

            	if (count($items) === 0) {
                	return $lastItem;
            	}

            	$items = implode($sep, $items);
            	$items = $items . $glue . $lastItem;
        }

        return $items;
}

// Test:
// -----

$speakers1 = array('Dan');
$speakers2 = array('Dan', 'Michael');
$speakers3 = array('Dan', 'Michael', 'Nathan');

echo 'Speakers1:<br>' . prettyList($speakers1) . '<br><br>';
echo 'Speakers2:<br>' . prettyList($speakers2) . '<br><br>';
echo 'Speakers3:<br>' . prettyList($speakers3) . '<br><br>';

// Output:
// -------
//Speakers1:
//Dan

//Speakers2:
//Dan and Michael

//Speakers3:
//Dan, Michael, and Nathan

?>

to_sentence()

/**
 * PHP Equivilent to Ruby's to_sentence method.
 * Example: 
 * to_sentence(array('a', 'b')) = a and b
 * to_sentence(array('a', 'b', 'c')) = a, b, and c
 * @param  array() $items   array of items to split
 * @param  array() $options array of options: 
 *         conjunction = conjunction string (default ' and ')
 *         seperator = seperator string (default ', ')
 *         conjunctionSeperator = conjunction seperator (default ',')
 */

function to_sentence($items, $options = null ) 
{
	$defaults = array('conjunction' => ' and ', 
					  'seperator' => ', ',
					  'conjunctionSeperator' => ',');
	
	if(is_array($options)) {
		$options = array_merge($defaults, $options);
	} else {
		$options = $defaults;
	}
	
	if(is_array($items)) {
		$lastItem = array_pop($items);
 
		if(count($items) === 0) {
			return $lastItem;
		}
		if(count($items) >= 2 && $options['conjunctionSeperator']) {
			$options['conjunction'] = $options['conjunctionSeperator'] . $options['conjunction'];
		}
		$items = implode($options['seperator'], $items);
		$items = $items . $options['conjunction'] . $lastItem;
	}
 
	return $items;
}