Children love cardboard boxes. It always happens without fail that a kid will play more with the sturdy box than the toy that came in it. Give them a washing machine or refrigerator box and watch out! Now, the inner child in all of us can play with cardboard boxes or even build our homes with them. Bloxes are building blocks made of corrugated cardboard. They come flat and pre-scored. With a little work, the cardboard folds into interlocking bricks. A case of 20 will cost you $59.95 USD.