Recently I was introduced to an interesting travel website geared towards people interested looking to do some long-term traveling: Earth Awaits. What it attempt to do is suggest places in the world you could live based on a budget.
In addition to filtering by the cost of living you can screen out places based on crime, pollution and miscellaneous other factors that might be important to you. They've pulled all of their data from Numbeo which is basically a crowd-sourced cost-of-living website. I remember referencing it a few times when planning extended travels.
I'm pretty sure the site makes most of its money through affiliate credit-card marketing via their travel page.
It's an interesting tool. I'd like to do another extended travel adventure at some point, and when that time comes I'll be sure to keep this site in mind.