They say the rule, which places a cap on the amount that banks can charge retailers each time a customer swipes their debit card, hurts customers and banks.

FORBES: New Bill Aims To Kill Durbin's Debit Card Fees

Eric Hughes, a cryptology expert with Simple Access, an electronic-commerce consulting firm, conducted his own experiment: at a technical conference, he issued a roll of pennies to every participant and explained that there was a one-cent charge, payable into a box beside the door, each time anyone entered the main room.

ECONOMIST: So many ways to pay online

Each time a consumer uses a credit card to make a purchase, the bank and card processor charge a fee that is approximately 2% of the purchase price.

FORBES: Senate Amendments Could Be Major Setbacks for Credit Card Issuers

My favorite is to get someone, a friend, to count the tics over some specified period of time, like a speech, and then charge the offender an agreed-upon sum for each offense.

FORBES: Do You Have a Speaking Tic?