Unless you have specialist skills (like, say, being a doctor) then you'll struggle to find places that will fund your travel costs. However, if you have a look at helpx.net, WWOOF and workaway.info then you will find lots of volunteering opportunities (often in an agricultural / domestic context) when you can volunteer in return for bed and board. The good thing about this sort of volunteering is that you can do several in a row, interspersed with travelling, and get to understand the local culture a lot better, whilst living extremely cheaply.