I've attached a new version which ignores products which don't specify a weight. I would have liked to have been able to attach both an admin and customer comment to the order denoting which products weren't included in the quote - but i'm under the impression that you can't use uc_order_comment_save until the next stage of checkout (review).

I'm not going to include any instructions yet, as it's only posted up here for testing purposes.

A few notes:
- After installing, make sure you select which shipping methods you would like to use. None are selected by default
- Make sure that all your products include weights. The other dimensions don't matter too much. They have no bearing on the actual quote, so I don't use them. I was not going to go to the hassle of writing "boxing" code that calculates package dimensions when multiple items are packed together. Reading about that by the developer of the osCommerce or ZenCart AusPost module developer was enough to turn me off that idea.
- The onus is on the store admin to make sure that their products are physically shippable - and to use the 'Product and its derivatives are shippable' property of each product. I'm about to re-include code which checks if $product->shippable is 'true'. If it isn't, the product obviously won't be included in the quote.