<?php
function array_map_recursive($callback, &$array) 
{
    foreach($array as &$val) {
        if (is_array($val) || is_object($val)) {
            array_map_recursive($callback, $val);
        } else {
            $val = call_user_func($callback, $val);
        }
    }
}
//voorbeeldje:
array_map_recursive('stripslashes', $_POST);
?>