That is a seriously great suggestion.

I won't be able to split it by card unfortunately as worldpay doesn't take that information from the module, but I see no reason why we can't change the text dynamically on the module e.g. Pay by WorldPay (2.5%) surcharge and then the percentage would change dependent on the amount fixed in admin by the shopw owner. It's not going to be a quick fix though, because I'll have to integrate it into the payment total side of things (the bit that give quantity discounts and tots up taxes) so I'll have to do a little rooting around to work out the best way to "fix" it. But yes, that is a very good idea.

Philip.