I recently picked up one of these little Sentry safes, about 1 foot cubed, give or take a bit. Electric keypad, heavy as heck for its size. Turns out it was empty, but it makes a nice little "fire-safe" cabinet for documents. I'm not concerned about locking it.

For some reason, I feel reluctant to tell exactly how I popped it open, but I will say it's disturbingly easy and fast. Bang that keypad off, and use your eyes.