I'm a bit confused with how to handle the new shipping rates.  For priority and expedited shipping, the USPS requires dimensions in addition to weight.  A customer who purchases 4 items will have a different size box then a customer who purchases 1.  I use oscommerce where I enter the weight of the product - not the size.  I was thinking of increasing the handling fee to account for the new rates.  What are others doing?

Thanks in advance.