I have a pet peeve for the sandwich shop industry. Each time I order my sandwich, I have to go through the same rigamarole of telling the cashier what sandwich I want, that I want it on wheat bread, that I don't want tomato, and I want yellow mustard instead of their nasty spicy mustard. This whole system is prone for error, as today I got a sandwich on white bread (which was surprisingly delicious).
Enter technology - what if I could just scan in my frequent flyer card at Firehouse subs and my previous order is automatically populated to the screen. This could be done with old fashioned plastic cards, HID cards, QR codes, Passbook, or even facial recognition. No more yelling over the crowd or racking my brain to figure out what else I forgot to mention. Bam --> sandwich. Just like it ought to be.
Sandwich people, you know who you are. Make this happen.