This one is so simple I hesitated to post it, but it's also so useful.

PluralHelper.php

<?php
 
/**
 * Returns a smart plural of the supplied word.
 * 
 * If there are more than one items in the supplied array, this function will
 * either add an 's' to the end of the supplied word, or return the optional
 * plural version.
 * 
 * @author  Kris Wallsmith <kris [dot] wallsmith [at] gmail [dot] com>
 * 
 * @param   string $text            The word you want returned
 * @param   array $array            The array of items this word is describing
 * @param   string $plural_version  An optional word to return instead of just 
 *                                  adding an 's' (i.e. "people")
 * 
 * @return  String
 */
function pluralize_if_many($text, $array, $plural_version = null)
{
    return count($array) > 1 ? ($plural_version ? $plural_version : ($text . 's')) : $text;
}
 
?>