SAN FRANCISCO (CBS 5) – Walmart is testing the next innovation in self-checkout. It’s an iPhone app called Scan & Go. You scan and items as you put them in your cart while walking the aisle, then head to the self-checkout aisle where your list is already waiting to be paid for, meaning you are able to avoid both a checker and the scanning process at the bottleneck that is the checkout area.

The new app does not have payment built in yet, but Walmart is in league with Best Buy, Lowe’s and Target in developing a phone payment system under the Merchant Customer Exchange.

READ MORE: Family Killed On Hike In Sierra National Forest Died Of Heat-Related Issues

The big question is how Walmart will prevent theft or shrinkage. Currently you place items on a scale when you use a self-checkout kiosk, and the weight of each item accounts for each one (along with a watchful clerk who monitors the self-checkout area.) But to have people unload their carts once they get to checkout would seem to defeat the whole purpose. 

READ MORE: Outrage Grows Over Racist Comments Targeting KPIX 5 Reporter Betty Yu

The upside for Walmart is to either deploy checkers to the sales floor where revenue is grown, not just collected, or to just reduce staff. Reports indicate Walmart spends and almost unbelievable $12 million a second on checker pay.

MORE NEWS: Santa Cruz Deputy Chief Appointed as New Interim Police Chief

(Copyright 2012 by CBS San Francisco. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed.)