Here's how it works: Order a coffee, and when the merchant swipes your credit card, you get your receipt by email. Leave your card on file with Square, and next time you visit the shop you can browse the menu and pay via smartphone.
Tech blog writer and Noe resident Xavier Lanier at GottaBeMobile shot this video of the Square in action at Spin City, featuring the cafe's owner/barista Maricar Lagura and her iPad.
Go say hi and you might get your own Square says Lanier:
"I didn’t just leave with a couple of cups of coffee on this visit. Maricar wouldn’t let me leave without taking a Square dongle for myself. Square’s apparently supporting this word of mouth campaign by loading loyal users up with extra Square dongles, which are compatible with iOS and Android devices."[Square, Inc.]
[Gottabemobile: Small Business Owners Love Square]