Here's how it works: Shop at Walmart and then enter your receipt number at the Walmart Savings Catcher website.
If an item you bought is on sale for less somewhere else, the systems finds it for you and refunds you the difference in a Walmart Electronic gift card.
Currently Savings Catcher tracks groceries and many health and beauty and drugstore type items, but not for electronics and toys.
It tracks prices in weekly sale fliers for a variety of stores, including Target, Publix and Kroger.
The savings tool is being tested in Atlanta and several other cities.