the keys to this working are:
1- Select it in a form element on the checkout page.
2- capture the selection in hidden form element on the confirm page.
3- capture the selection in a session variable on the confirm page.
4- Use the session variable value in the triggers for the shipping rules.
on the checkout page create your select list:
<select name="shipType" id="shipType">
<option value="Local Pickup">Local Pickup</option>
<option value="UPS">UPS</option>
</select>
on the confirm page, create a hidden form element of the same name, and set it to capture the value posted from the checkout page:
<input name="shipType" type="hidden" id="shipType" value="<?php echo((isset($_POST["shipType"]))?$_POST["shipType"]:"") ?>" />
Now add a Set Session Value server behavior.On the server behaviors panel, click the plus button and select eCart -> General Set Session Value.
Set the Name to shipType.
Set the trigger to any form post
for the value, click the lightning bolt and select the shipType form element.
Now in the eCart object, set the trigger for the local shipping rule to be Based on session variable value:
If the session variable "shipType" has a value "=" to "Local Pickup"
and set the trigger for UPS shipping to be Based on session variable value:
If the session variable "shipType" has a value "=" to "UPS"