"Benches in a stack" from Martha Stewart Home & Decorating
"If all the bookshelves you find in stores are too tall, too wide, or too unwieldy, consider stacking sturdy wooden benches to make a streamlined shelf that's just right for your space. Ours is made from three benches; two would work as well, but don't stack more than four. Paint the benches (we used a latex semigloss paint) to suit your decor. To assemble, stack 2 benches. On the front of each leg of the top bench, drill a 45-degree hole (centered 1 inch up from the bottom of the leg) through the leg and partway through the top of the bench below. Use a long wood screw to attach the pieces (screw size will vary depending on the thickness of your bench legs). Repeat on back legs. Stack another bench on top (if desired), and repeat to attach. Fill and finish the holes."