Why does it have to be limited to smartphones? What prevents a system similar to M-Pesa built around a cell service provider offering a BitPay like service? Does anyone here have direct experience with M-Pesa?
My only issue is that the application platform is so widely adopted that this may take more time than is efficient to establish. It would of course open the market to everyone with a phone, but everyone wants a smartphone.
Coinvestor (Ryan)