How to keep a three year old busy in the grocery store

Ok we were in Foodlion yesterday and my daughter who is three is asking for everything in the store. I noticed she took notice when I got a coupon out of the smartsource coupon thing on the shelf, so I decided it was time for a game. I told her ok game time, let's look for coupons. She said you dont have your computer I guess she thought the only place you could get coupons are on the computer. After I finished laughing I explained to her the little machines had coupons too and her job was to ride in the cart and help me look for them. She started looking, if she didn't see any she would say no coupons here mom and would get really excited when she found one. She kept saying "this is fun mom." Managed three things out of this game, kept her busy, she found coupons I didn't see, and saved money because she was so busy looking for coupons she quit asking for things. I think this is going to be our official grocery store game.