I couldn't find hummus the other day. I thought, "Hummus, must be under condiments." It was under Deli. I am assuming the scanners search process would be based on categories, rendering you useless as we still won't be able to locate these item even if we know what "we" consider them. If a keyboard were included on this scanner than it may be too bulky, but would be SUPER awesome. Bulky scanner would have to be connected to a shopping cart, hassling those who carry bin's rather than push carts, Maybe a grocery item search station may serve customers better.

The reason we do pile things in to our carts is because of marketing. "You want it, might as well.; item grabbed." An item scanner would assist you with inventory management while maintaining a budget, but let's be honest. A simple grocery list will suffice. Chances are you've already bought everything in the grocery store before and know their prices even on sale. A grocery list reminds you what is necessity to purchase versus what is desired. The only reason we want extra stuff is because of large corporations pushing advertisement down our throats subconsciously. Another option is to use a hand held bin instead of a cart; the (people will eat less when serve on small plates) example may be applied. But of course I understand if you are shopping for more than one person.

response to 2: stores can already track what we buy, e.i. Target, but they can now better track what we are unable to find and may restock inventory more appropriately