Walk through a neighborhood arts and craft fair and witness the convergence of payment systems firsthand: the jeweler manually makes a carbon copy of your Visa or will take a check if it is all you have; the glass blower accepts credit and debit cards with her wireless card reader; the woodcarver submits all payment information on his portable laptop; and the t-shirt vendor lets you take home a souvenir after submitting your card information via iPhone.1 From paper to Wi-Fi, the payment mediums and the systems through which they travel are becoming increasingly interchangeable.