Shopping List Manager for Windows Phone 7 organizes your grocery runs
Create a list, add items, and you'll get a checklist to mark off items as you add them to your grocery basket (or cart, if that's how you roll). Shopping Lists Manager will also optionally hide checked items so they're not cluttering up your list view. Better still, you can register and then sync your lists between two devices -- very handy if you and your roommate or significant other want to collaborate on purchase planning.
Download Shopping List Manager for Windows Phone 7