I was surprised to see that GroceryGuide has good coverage in my area (which is fairly rural). They had up-to-date sale data from all of the major local grocery store chains, though were missing a couple of the smaller, locally owned markets. The site lets you search up to two grocery markets in your area at once, and for up to three items (or all items on sale). Results can be organized by rating, brand, category, store, or sale ending date.

Users can create a printable shopping list, which is automatically segmented by store. Members are also invited to rate and review products and stores. For most food products, the site suggests recipe ideas, and users can create alerts around specific items and be notified when things go on sale -- so, as the site suggests, if you find a recipe you like, you can find out when the ingredients can be had on the cheap. I do wish the site allowed you click through directly from ingredient lists to search your local shops, though.

GroceryGuide is a helpful local site that makes planning your shopping trips easier. With a little visual love to make browsing through sale lists a more pleasant experience, and mobile support so you could check sale items in the store (i.e., to find out if an item is on sale at Store B while shopping at Store A), it would be even better.