I have been very excited over this since I found out about it a few weeks ago. The ALL YOU Magazine has on their website a collection of circulars from grocery stores all over. You can put in your zipcode, choose what stores you want to search through their sale ads, then enter in your shopping list and it will come up with the sale prices for the items on your list and what store the sale prices can be found at.
bread $1.29 at Tops
eggs $1.12 at Walgreens
cheese 8oz Heluva good $2.00 Price Chopper
chicken $1.98/lb at Hanover
Then you can print your list (with the prices and what store has the sale) and if you are going to be shopping at walmart you can use this list to easily tell the cashier what store you are pricematching to and what the price is. (walmart pricematch policy found HERE).
Just check and make sure that the sale prices are still lower than walmarts price before you tell the cashier you want to pricematch.
Try it out yourself and let me know what you think, ALL YOU circular.