Have you considered adding bitcoin as a payment option? Seriously, it's nearly free and easy to manage, even with the rapid price changes. Plus you get extra attention by adding your store to the growing directory of merchants who accept bitcoin.
and yet it doesn't actually solve his original problem as the number of people who use bitcoin is certainly negligible in the grand scheme.
In the grand scheme, bitcoin, (or a derivative technology) could certainly become a game changer in the not too distant future. Accepting bitcoin probably doesn't hurt.