Reuters was tipped off to a survey that reveals Walmart, the world's largest retailer, is testing a new system that would allow customers to scan items with their iPhone then quickly pay at a self-checkout counter. The "Scan & Go" feature won't let you pay with your phone, at least not yet, but rather than scanning each item individually in line, shoppers will be able to quickly transfer their list to the kiosk and pay in one quick step. The hope is that the new system will dramatically speed checkout times and reduce congestion in the stores. The trial is taking place at the supercenter Rogers, AR, where the entire event will be monitored and recorded for research purposes. Participants are being rewarded with $100 and a $25 gift certificate towards their shopping experience. When or if "Scan & Go" will be delivered to John Q. Public remains to be seen. But we're sure fans of rolled back prices are eager to see it go live.