A cigarette case is a metal, hinged case usually used for storing, what else, cigarettes. Most are shallow enough to store only one row of smokes, which probably amounts to half of a pack. Generally, they will also have a spring-loaded retaining arm to keep the cigarettes from falling out when you own the case.
Bright, shiny metal cigarette cases have a habit of showing up in movies and shows where the producers couldn't afford to get licensing permission from a tobacco company.
So what in the name of Bob am I doing talking about Cigarette Cases when I don't even smoke? Because they are quite useful even to non-smokers. My case is perfect for storing my PCMCIA and CompactFlash Cards, keeping dust and dirt out of their little conenctors. It's also great for storing seldom used things like Credit Cards and my Video Rental Card. Becaus they're metal, otherwise breakable things can be put in then, keeping them from being bent when put in a pocket.
Many also have the added bonus that, being metal, the inside is highly polished and makes a great on-the-run mirror.