This is the kind of thing I wish I’d thought of years ago and may have to try at some point.
You and a friend write shopping lists full of nonsense items for each other. Neither of you know what’s on your list until you start asking questions. Yes, asking questions. With list in hand, you walk into your department store of choice, find one of those employees that always seems to be wanting to help you with something and start asking where you can find things. Whoever gets through the most items without getting blown off or told off wins. If you’ve got funny friends, there is much potential in this activity. There is video proof of this potential here and here.
Have fun, and let me know how it goes if any of you give it a shot.