If you've ever had a chest in the attic locked for years or even a shed at a rent house unopened for years, chances are you might have used a combination lock to keep prying eyes and thieves away from whatever is valuable enough to keep locked up. I know I use them instead of key-based locks just because I can't stand keeping track of zillions of keys.

Okay, the next big question: ever forget the combination to a lock? If it's a Master-brand lock (most of them are), did you know that you can harmlessly crack it pretty easily and get that darn thing unlocked with a minimum of fuss? Just don't tell any nearby, part-time thieves about this.