Custom token-based redirect after registration

Oops in the above please replace [node-link] with [join-link]

My solution works, however i wonder if there's a more elegant way?

I appended my token value: "?redirect=/node/...." to the end of [node-link] in the body of the invite email. Before the invite module clears my redirect parameter I grab it in my custom module function (see below) that stores it in the $_SESSION var - which is accessed later in a user form_alter to set $form['#redirect'].

function your_module_user($op, &$edit, &$account, $category = NULL) {
	if ($op == 'load') {
    		if ($_GET['redirect']) {
			//Store the redirect parameter for a user who was sent an invite email
			//See form_alter - $form['#redirect'] for use of $_SESSION['redirect']
			global $_SESSION;
			$_SESSION['redirect'] = $_GET['redirect'];
		}
	}
}

Is there a better place to set my $_SESSION var then in the hook_user?

Also note that i unset $_SESSION['redirect'] in a user submit handler.