A new Apple patent, published today, might help save your lunch. It describes an idea for an app that lets you use nearby strangers as mobile ATMs.

The idea for what Apple calls an "ad-hoc cash-dispensing network", is that you launch the app and tap in how much you need. The software uses your location details and broadcasts your request so that everyone else with the app in the vicinity is notified of your predicament.

When someone agrees to stump up the money, you are told their location, and go and pick up your cash. Other iterations of the idea include a map in which would-be bankers are indicated with either a star to say they have accepted your request, a question mark to say that they haven't or a cross to say they have declined.