With Homax’s Tarp Hook you can reuse your empty plastic water or soda bottles by turning them into weights to keep your tarp in place. You can also make a bird feeder or insect trap out of ’em, clip ’em to your pack to carry some extra water, or replace those nailed-up baby-food jars with ’em.
Simply screw the tarp hook onto the bottle in place of the normal cap. Then fill it with the appropriate stuff for your application.
A four-pack of tarp hooks runs about $5.