re: Engineering Idea

Right now, you could implement an app that knows your location, so when you pull into the parking lot, your normal order is automatically sent inside, you walk in or drive up, scan the barcode on the phone or use NFC, and they hand you your stuff while your payment is processed using that scan.

This is already on the way to Starbucks. They are halfway there with the ability to use their app to pay for drinks.

Also, you can imagine the possibilities of this kind of process being in place at many other service based establishments. Restaurants, malls, movie theaters, big box stores, etc.