Trash can bicycle baskets. Just drill quarter-inch holes under the rim along one side of the waste baskets, and a few more in the bottom for drainage in wet weather. Then use nylon rope to tie the bicycle baskets to the rear rack. The baskets may rattle a bit when you hit a bump in the road, but they can tilt up to be emptied of leaves and other debris. To carry a dozen library books or a couple days' worth of groceries, use 16-quart bins, which are just the right size.