Hi Shon7,
Shortly after concluding my commercial ticket I considered that very same thing. I initially contacted the Peace Corp and was amazed to find they had little use for pilots, they mostly want doctors, dentist, nurses or teachers etc… who can go in a teach or pass on a skill to impoverished people and places. But the lady I was communicating with suggested on organization called “The World Relief Organization” who operated relief flight, air ambulance operations and volunteer charter flights throughout the world. This group also works on contract to the UN and NATO when needed.
But after contacting them I was told they require a CAA or JAA license, because they mostly fly into or out of Europe, Africa and the Mid-East. They also had substantially high minimums for someone carrying a CAA/JAA license not already employed by a jet operators or regional turboprop carrier, about 1,200 total time and 250 multi.
And they required several documents including a European work permit, so I just gave up and started flying jumpers and sightseers on the weekends and working at my father’s law office during the week.
Good luck with the search though.
PS If I still had the contact info I would give it to you, but that was nearly three years ago and it has since been tossed with the trash.
James