I've always thought that the real solution for the "too many cards" problem is to get all credit card companies to agree on a card-less payment protocol that an

I've always thought that the real solution for the "too many cards" problem is to get all credit card companies to agree on a card-less payment protocol that anyone could implement on any device. (And in the process, make all the transactions a lot more secure by using modern cryptography.) Alas, I'm afraid that kind of disruption cannot be brought forth in a market context...