Popsugar Living Sustainability Uses For Old Books 21 Uses For Old Books 31 May 2018 by Hilary White View On One Page Photo 13 of 21 ADVERTISEMENT () Start Slideshow Share This Link Copy ← Use Arrow Keys → 13 Hidden Piggy Banks Hollow out one of your old books to hide your cash and other valuables. No one will ever guess your secret hiding place ($17)! secret hiding place $17 from etsy.com Buy Now Previous Next Start Slideshow SustainabilityBudget TipsBooks