To give the user an idea of where hes at in the checkout process i modified the THEME_uc_cart_checkout_form() and used
$form['#submit']['uc_multipage_checkout_checkout_page_submit']['0']
Is that the "correct" way to detect a stage - or is there somewhere a $var that I havent seen?
<?php
THEME_uc_cart_checkout_form(){
//1
if($form['#submit']['uc_multipage_checkout_checkout_page_submit']['0']=="billing_details"){}
//2
if($form['#submit']['uc_multipage_checkout_checkout_page_submit']['0']=="shipping"){}
//3
if($form['#submit']['uc_multipage_checkout_checkout_page_submit']['0']=="payment_details"){
//4 checks the previous
if($form['#submit']['uc_multipage_checkout_checkout_page_submit']['1']=="shipping"){}
?>- it would be cool with some kind of generic $form[#stage] though 