We do this with a javascript that builds an add to cart button on the fly. if you put a hyphen between products they will all go into the cart using the cart_links module something like:
<?php
<a href=mysite.com/cart/add/p123_a101_q2-p456_a1o3_q3>ADD LOTS OF STUFF TO CART</a>
?>This is totally off the top of my head but it should add 2 of product 123 with an option and 3 of product 456 with a different option using a single click.



Joined: 08/07/2007