I only use couple of cards, it would be nice if some of the major store companies would get into the passbook. I went with a third party company and created couple of extra cards and they somewhat work. I manily use Walgreen's and PetSmart, I'm thinking of using Dunkin Donuts passbook, since I'm going there more often. Plus I might either tryout the TicketMaster or LiveNation ticket passbook, if I go to Mayhem Fest.