Twitter Creator Unveils Phone Credit Card Reader

Twitter co-founder Jack Dorsey gave the public its first look at “Square” today, a free credit card reader that will plug into the headphone jack on your phone. Small business owners will be able to plug the 1-inch device into their phone, swipe their customer’s cards, and have them sign on the phone’s touch-screen. Dorsey didn’t reveal how he’ll make money with Square, but he mentioned a tiny charity donation attached to each transaction.

He said the device had been inspired in part by the “immediacy” of Twitter, and in part by the “clean slate” the financial crisis had created. And he knew he’d have one customer right away. “My co-founder is a glass artist. He sells things that people don't need—$2,000 glass faucets,” he explained. “They're beautiful. If he could not take credit cards, he wouldn't make the sale because no one carries around $2,000 in the cash.” (More Jack Dorsey stories.)