Square

Investors figured that new J.C. Penney CEO Ron Johnson's "Fair and Square" pricing strategy wouldn't be a hit right away, but no one expected the recently remodeled department store chain would be this earnings season's biggest disaster.

When money and friendship mix, the results can get awkward: You front a friend some cash, and then what? Venmo, an app that helps you exchange money through mobile devices, is designed to remove that awkwardness and replace it with something social, and even fun.

Are you a conservative, pays-with-cash sort of consumer or a smartphone-wielding early adopter? As it turns out, what's in your wallet may say more about you than you think.

What could be easier than paying for something with a wave of your phone? Not much. But there are prices to be paid for the frictionless ease of mobile payments, and they aren't all obvious.

Square makes it much easier for even the smallest retailers to accept credit cards: The mobile payment firm offers easy to use hardware that plugs right into iPhones or Android devices. But at least part of its new high price tag probably derives from the fact that its founder, Jack Dorsey, also co-founded Twitter.

The smartphone revolution is about to upend another business: credit card processing. With Google's new Android pay-by-phone app and Square's new transaction hardware for iPhones, your plastic could become obsolete.