Putting in a few hours of work during your travels can not only score you a free place to stay (and maybe some meals, too), but it can be an interesting experience and a good way to meet locals and fellow travelers alike. Websites like Workaway.info
list part-time, (usually) unpaid work opportunities all around the world that can nicely fit a flexible traveler's schedule, lifestyle and budgetary limitations.
And by joining Trustedhousesitters.com
, you're eligible to apply for housesitting gigs worldwide, giving you a free place to stay in exchange for watching over someone's house (and, usually, their pets) while they're away.