I used this for formating bytes, btw:

/**
* filesize function.
*
* @access public
* @static
* @param mixed $size
* @param int $round. (default: 0)
* @return void
*/
// http://www.veign.com/code-view.php?type=web&codeid=74
public static function filesize($size, $round = 0) {
$sizes = array(‘b’, ‘kb’, ‘meg’, ‘gb’, ‘tb’, ‘pb’, ‘eb’, ‘zb’, ‘yb’);
for ($i=0; $size > 1024 && isset($sizes[$i+1]); $i++) $size /= 1024;
return round($size, $round).$sizes[$i];
}