PricePlunge offers the Travelon Expandable Backpack in Aqua, Lime, or Berry bundled with a packing cube for $10.99. Coupon code "SANDCENT1" cuts that to $10.44. With 99 cents for shipping, that's $25 off and the best price we could find. It folds into a pocket for easy storage and features two zippered front pockets and adjustable straps.