Twitter Founder Pushes Mini-Credit Card Reader

Jack Dorsey revolutionized the way many of us communicate when he launched Twitter.

Now, he's hoping to revolutionize the way many of us buy things with his latest brainchild.

A new company he heads is coming out with "Square," a square-shaped mini-credit card reader that attaches to any smart phone and could enable small merchants anywhere who can only take cash now to accept the cards instead.

"It just fits in to the audio jack of your mobile phone," Dorsey explained to "Early Show" co-anchor Harry Smith, "and it works on your iPad, your iPod, your Android phone, and you plug it into the top, you load the software, and you can put in an amount, and then you can just take a credit card, swipe it. It goes up to see if there's (money available on the) card, and then it asks to sign with your finger. So you simply sign with your finger on the screen.

"We think it's going to be used by a lot of babysitters, dog walkers, hairdressers, flight instructors, piano teachers -- anyone you can imagine paying with a credit card who you can't today. This makes it very, very easy to accept cards."

Dorsey told Smith all about Square, and called the Twitter phenomenon "humbling":