"It's like jeans for your house." Okay, so maybe no one ever says that about Recycled Denim Insulation ($6 and up), but it is made from jeans, and it does go in your house. This unique building product is made out of recycled denim and other cotton textiles, and features a natural fire retardant that also helps to inhibit mold and mildew. And thanks to the fact that it contains no chemical irritants and has no fiberglass itch, you can install the stuff easily without having to don a Hazmat suit. Available at most home improvement stores.