We’re not sure how safe these are, but these Moon Shoes sound like they must be a lot of fun to use. Described as a “mini trampoline for feet” the moon shoes are designed to defy gravity so that you can jump higher and higher. And supposedly, all this jumping fun leads to improving your coordination and balance. The moon shoes will fit any shoe size for woman up to size 7 and any shoe size for men up to size 9. They retail for $29.88.