I just learned about the Whole Foods Kid's Club this morning. I don't know for sure that every store has it. I can't find anything on their website. But, here's what they do at our store -
Your kids can become members of the club for free, without signing any paperwork or anything annoying. They give 'em membership cards. When you come to do your grocery shopping, they get to pick out a free snack. There's a store rack full of goodies that they can pick from - juice box, fruit leather, raisins, sandwich cookies, cereal bars.... Or, they can take their card to the bakery for a free .99 cookie!
I remember being a member of Safeway's Cookie Club when I was a kid. It was so exciting to be able to hand the baker my card & get my cookie. It makes a kid feel so grown-up to have a card. Getting my first library card was also very momentous.