a website I became a member of a few years ago: http://www.truetravellers.org/
in the words of an Administrator of the site:
“Frustrated by the “volunteer in Asia, volunteer in Africa, volunteer in South or Central America, but first pay us lots of money” opportunities? We are too.
Our organization is a network of individuals that share information about no or minimal fee meaningful travel and volunteer travel opportunities around the globe. These opportunities can include anything from volunteering at an orphanage, to a festival, to wildlife conservation to you name it.”
it’s a worthy online forum, though I haven’t often found myself active there, I get a little frustrated with the interface of the website from time to time, & to this day I have not been able to use the little blog function that is supposed to be integrated into my profile there