Need help on shipping configuration

I have two types of shipping modules installed USPS and UPS this is across USA so when a customer comes to the shipping page both options are made available.

I would like to be able to display only one or the other for some products, and both for others. This is not to be based on address or weight or zone just based on product.

Basically I want to control at product level which option the customer sees can one of you wizards help please.

The usual question - what happens when the customer puts one 'UPS' product and one 'USPS' product in his cart?

stevesh:

The usual question - what happens when the customer puts one 'UPS' product and one 'USPS' product in his cart?

Then we swill ship both items using the cheaper of the two methods, or the more possible, let me explain, I want to make the UPS availble for items that cannot be shipped USPS (eg: flammable products like dry fuel) so if a customer orders a flamable product and a non flamable product we will ship using UPS and absorb the cost difference.