Two things that you never know when you’ll need are flashlights and bottle openers. Power blackouts and engine trouble can happen at any time, requiring an extra light source. Really, there are a thousand types of emergency situations that might require a flashlight. As for bottle openers, they’re needed whenever you’re at a party or special event where bottled beverages are readily available, but the one bottle opener that someone thought to provide has somehow gone missing. Since you never know quite when you’ll need a flashlight or a bottle opener, it’s a good idea to attach them to something that you’ll always have on hand … like your keys.