You may be able to reuse your mattress in your own backyard. If you have children, your old mattress might be the perfect protective layer for the bottom of a jungle gym. It might also be a creative substitute for that expensive trampoline your kids have been begging for. Remember when your little ones could play for hours with an old moving box, turning it into a fort or whatever their imagination conjured up? Your mattress could be anything your child imagines. Again, just be sure to have it professionally cleaned. Even if you think you've kept your mattress in tiptop condition, body sweat and dust mites, invisible to the naked eye, can cause illnesses [source: Mattress Firm].