function str_replace_first($search, $replace, $subject)
{
        $retval = $subject;
        $pos = strpos($subject,$search);
        if ($pos !== false) {
                $retval = substr_replace($subject,$replace,$pos,strlen($search));
        }
        return $retval;
}


the above function would be useful in the str_functions, would probably be faster in c.. and i bet some people use something similar atleast once in their life :D