I don't know about you but when I shop at supermarkets and hypermarkets in the evenings, I'd make sure that I check out before 9:30pm before the crowd builds up.
One thing that keeps me occupied while waiting in line is the point of purchase displays. My favorite POP display item has got to be batteries. Why? Because more often than not, I tend to forget to get them when I go shopping and having the display smack right in front of you when you check out is such a big help.