[mynameisvlad]

Canada switched to that sort of system when chip+PIN was introduced many years ago, so the hardware is available in North America as well from major providers like Verifone. It's just that you need more terminals for concurrency with such a system, and it's not integrated into the full POS system so the waiter/clerk has to actually input the amount. Nobody wants to pay extra if they don't have to, which is why it's not as quick to rollout in the US. Chip+signature in the US still doesn't require the customer to interact with the payment terminal, so I doubt US restaurants and other businesses will be quick to switch to this or other handheld terminals.