Yes and the lack of a display on the smart card nixes any added information value of the effort which is why I suggested 2D Barcoding as a win-win. The retail perks of having more information given to the customer and the retailer is going to offset any concerns of cost to implement.

Plus the interface on the phone would have the option to challenge the bitcoin account holder for validation, meaning the amount paid will be verified, and it can't be stolen and abused by simply physically having the phone.

What I don't get is why anyone would make effort to go backwards in the tech tree? Smart cards are just another point of failure and expense when we already carry smart phones?

I've been doing work with point of sale (professionally) for over 9 years now, and you can trust me when I say that I've got no love for the existing infrastructure.

I'd push for a in-store product registry with Aztec(public domain) or similar 2d barcoding on the items for information and purchasing. Scanning one of these items will bring up the entire history of the item which can in many cases add value to the store/products.

When you spot something you wish to own, you'd scan it (take a picture) with a mobile app that would handle the purchase and authenticate. You can place the item in your cart and at the checkout the cashier scans the items a second time to confirm which ones are paid and which need to be paid to continue.

This would allow the retailer to do promotions on items and track those sales, while still allowing everything else to be purchased normally. Retailers LOVE solutions that they can ease into slowly without shutting down the store for a few days.