Many of us will occasionally forget to pick up important ingredients when visiting the grocery store, but that absent-mindedness may not be a problem for much longer. A handful of Giant Eagle and Safeway locations are now using a new marketing service, InMarket's Mobile to Mortar, that relies on Apple's iBeacon to send proximity-based notifications while you're wandering the aisles. In addition to offering on-the-spot coupons and rewards, the system can remind you what's on your shopping list at just the right moment. It can also send an alert when someone adds to the list; if the family runs out of juice while you're in the store, you'll know to buy another jug before you reach the checkout line. Only certain Giant Eagle and Safeway outlets in Cleveland, San Francisco and Seattle are using Mobile to Mortar at launch, but InMarket promises more news in the months ahead.