QR codes or something like it will eventually be the way Dwolla and Paypal do mobile-to-mobile transactions. I've thought of a mock up of just using ONLY QR-lik

QR codes or something like it will eventually be the way Dwolla and Paypal do mobile-to-mobile transactions. I've thought of a mock up of just using ONLY QR-like codes to transfer money between two people in the same room, it would be fast and easy and assuming you used your Dwolla pin as you confirmed the amount you were spending/charging, it would work perfectly.