Stormtec Stormbags seem to be a neat alternative to sandbags. According to Boingboing, the lightweight bags are easy to transport to disaster sites. Once you're there, you can simply immerse the bags in water, and within 5 minutes, the polymer crystals inside the bag will expand to create a 33 lb. bag. The even stranger part is that the bags are completely reusable! Once the storm has passed, you can let the bag dry out and it will shrink back to its original size and weight! Pretty crazy. The Stormbags cost $7.00 each at the Stormtec website, or $340 for a box of 50 bags.