I had a bad "shopping cart line" experience at Sam's Club a few years back. We got in line behind two ladies who were holding a few items. I'm thinking, "great, the cashier will process them quickly and we'll be next." However, two of their friends then rolled up with two full shopping carts and joined the ladies in front of us. I made a scene and even upbraided their gentleman friend who was obviously trying to distance himself from the situation. Oh well, too bad I wasn't billing by the hour that afternoon!