Can You Turn an Expense Into an Income?

Can you get something for free and then resell it? Can you turn an expense into an income stream? I've had people offer me stuff. A a friend of mine had some land some floor mats for his car. And i was able totakei get some income off of it, turning an expenseinto an income stream. There are all kinds of great new ideas that are coming out. So can you to a house swap while you're on vacation? What a cool way to finance vacation.