Just because you don't have cash doesn't mean you don't want and need things. According to authors and business gurus Karen Hoffman and Shera Dalin, it's time to get a little creative. Most people have a skill they can use—it's just a matter of figuring out what that is and how to use it to get something else. From piano lessons in exchange for haircuts to an engine tune-up in exchange for house painting, The Art of Barter offers step-by-step instructions in: