In the same way that you yearn for that foreign land, tropical beach, or unchartered wilderness, there is likely someone in that same land that yearns to see yours. House swapping is exactly as it sounds: you coordinate dates and plans through one of several websites, and then trade houses for the agreed-upon time.
This is a great option since you will not only save money, but you will benefit from having someone to watch your house while you are away. It also helps make a connection with a local, since they can provide great recommendations for things to do and see around their hometown that you might have not otherwise read about in a travel guide.
Resources: Some examples of the house swap networks with great reviews include www.guesttoguest.com, www.HomeExchange.com, and www.homeexchange.com.