I picked up a Cannonade kids trailer at a thrift store for $10 and converted it to a touring trailer. I removed the fiberglass tub so all that was left was the axel and frame. Using some 1" X 1/8" aluminum angle and pop rivets I made an adaptor frame for a plastic storage box from Wal-Mart and used bungee cord to attach the plastic box to the frame. The plastic box has a lid so everything inside stays nice and dry and the bungee cords allow quick and easy removal of the plastic box from the trailer frame. This allows carrying the plastic box around the campsite and leaving the trailer attached to the bike. The trailer has quick pins holding the wheels to the axels so I normally remove one of the wheels and place it in the storage box to help prevent theft.