There are certain things, like tents and obscure kitchen appliances, that tend to sit in closets much more than they're used. Even cars usually sit empty 23 hours out of the day. And when you think about all of the money we spend buying these things—and how much energy goes into making them—it makes sense to try to get more out of them. Sign up for a site like Neighborgoods or Yerdle, list your stuff, and look there first before you buy something you might need once. Or if you want to do it old school, use this as another excuse to get to know your neighbors—so the next time you need a drill you can just knock on their door instead of going to the store.