What Jeff said, and the bottom line is: store the object in $_SESSION.
Just make sure you include the class definition before you call
session_start().
<?php
include_once('lib/myclass.php');
session_start();
if ( empty( $_SESSION['myobj'] ) ) {
$myobj = new myclass;
$_SESSION['myobj'] =& $myobj;
}
else {
$myobj =& $_SESSION['myobj'];
}
// etc..