Jack Dorsey, the thirty-five-year-old co-founder of both Twitter and the smartphone-based payment system Square, doesn’t simply envision a post-plastic world of commerce. He says he lives it every day in San Francisco, where he walks into cafes and restaurants with his phone in his back pocket wirelessly transmitting his photo-linked “Pay with Square” account details to cashiers, who then charge his tab. “The future has already arrived,” Dorsey told an auditorium of 200 U-M students in September. “Our challenge now is distributing the future to everyone.”

That’s why Dorsey and his entourage were in town, evangelizing with free T-shirts and food from Mark’s Carts vendors who use Square systems. The company says it has a thousand commercial subscribers in Ann Arbor, ranging from artists to taxi drivers to food vendors, who like the simplicity of working with a single billing service as well as Square’s analytics, which help them identify frequent customers, best-selling products, busiest times, etc.

“It’s a leap forward from the old system of counting coffee cups coming out of the dishwasher to know sales volume,” Dorsey says. And with mega-client Starbucks slated to come aboard in time for the Christmas rush, Square’s version of e-payment utopia is about to get another major caffeine jolt.