Instruction: What are some useful ways to repurpose a cardboard box?

Response: That depends on the person and what they find useful. I might find a box useful for clearing my desk of all the mess I accumulate throughout the week. Meanwhile, my kids would much prefer to turn the box into a play house, a spaceship, or maybe a jail to imprison each other in.  A cat might repurpose it as a hiding place or as a new scratching toy.