OpenTable made a name for itself by giving people a way to make restaurant reservations online, and now looks to make a similar splash for what happens when people are done eating. So far thats limited to about a dozen establishments in San Francisco, where OpenTable is headquartered; OpenTable began testing the service last July, shortly after it acquired mobile payments company JustChalo, though the feature was not available to the public. On the back-end, the payments are being handled using existing OpenTable reservation and guest management systems, the company says.