Instead of replacing credit cards new cellphone technologies like Square rely on them. You win a bet but the loser does not have enough cash on him to settle it. If he has a credit card and most people usually do there is finally a solution. A number of big and small companies - including eBays PayPal unit Intuit VeriFone and Square - are creating innovative ways for individuals to avoid cash and checks and settle all debts public and private using their cellphones. Cellphone Payments Offer Alternative to Cash...
(source)http://www.nytimes.com/2010/04/29/technology/29cashless.html?hp