Store shelves haven't changed much since the advent of the UPC barcode, but a new company called ShelfX is looking to change that a bit by bringing RFID cards, QR codes, and smart shelves to your supermarket. The first implementation of the technology is the (unimaginatively) titled Vending Fridge, which unlocks after it recognizes your account (containing your payment method) from an RFID card or an iPhone app that'll scan a QR code on the fridge. Once unlocked, you can peruse the sodas, sandwiches, fruits, or other items in the fridge and remove what you'd like. After closing the fridge it'll figure out what items were removed (even if you moved stuff around you'll only be charged for missing items) and it'll automatically process the payment. The system also keeps track of stocks as they get low, and it'll send once-monthly remittances to shop-owners with the revenue generated minus a fee that ShelfX keeps for itself. We're all for neat tech demos, but this fridge is actually up for pre-order now for $599 ($299 if you go the DIY route and retrofit your current fridge) — the next step is to see this in your corner deli.