Exactly. I had this idea ages ago - ever since smartphones became ubiquitous, all the technological pieces have existed - it's just a matter of getting some competent engineers to put them all together.
You could have all kinds of cool extensions, such as ordering ahead of time on your phone and having pick-up drive-thrus at big box stores and supermarkets, where payment could be taken care of automagically, via NFC. You could sort not just by price, but by price + time/distance from current location (the latter for gas costs) + tax, sort of like Hipmunk's "agony" sorting feature for airfare. You could make a shopping list and the app would optimize which stores to buy which items at, and in which order you should visit the stores, based on things like individual item costs, geographical locations of stores, opening/closing times, delaying of purchasing of frozen foods, etc.
But retail outlets will never cooperate. They'll be the big losers here, as the last barriers to comparison shopping disappear and customer loyalty is replaced by the cold, hard facts.
You could have all kinds of cool extensions, such as ordering ahead of time on your phone and having pick-up drive-thrus at big box stores and supermarkets, where payment could be taken care of automagically, via NFC. You could sort not just by price, but by price + time/distance from current location (the latter for gas costs) + tax, sort of like Hipmunk's "agony" sorting feature for airfare. You could make a shopping list and the app would optimize which stores to buy which items at, and in which order you should visit the stores, based on things like individual item costs, geographical locations of stores, opening/closing times, delaying of purchasing of frozen foods, etc.
But retail outlets will never cooperate. They'll be the big losers here, as the last barriers to comparison shopping disappear and customer loyalty is replaced by the cold, hard facts.