I think you'll need to code a loop through the shipping rules to see which ones aren't 0, then create a session wit the rule names.
for example on a cart named eCart1:
<?php
$_SESSION['shipName'] = "";
if (!$eCart1->Rules_EOF("Shipping")) {
while (!$eCart1->Rules_EOF("Shipping")) {
if ($eCart1->RuleLooperValue("Shipping") > 0) {
$_SESSION['shipName'] .= "".$eCart1->RuleLooperName("Shipping")." ";
}
$eCart1->Rules_MoveNext("Shipping");
}
$eCart1->Rules_MoveFirst("Shipping");
}
?>
then on the bindings panel, clic the plus button, and select Session, name the new binding shipName and use that binding in the store order summary