My time living and working overseas as a PCV profoundly affected who I am today: I am more flexible, more thoughtful, less reactive, more comfortable with ambiguity and complexity than I was before, and more willing to risk being uncomfortable(emotionally and physically). I may not yet be where I'd like to be with all of those qualities and maybe they would have come with age anyway, but I attribute much of who and how I am to having lived and worked among people who are more typical of the world's population than those I had previously lived and worked with.
Most people in the world don't have indoor plumbing or electricity; it's good to learn not to take those things for granted. Many (most?) cultures have communication styles that are much less direct than the straight-talking-let-it-all-hang-out ideals of my upbringing. It was good to witness the very long process of consensus decision making at staff meetings in the Solomons. Many (most?) cultures place more of an emphasis on relationships than on time, and I'm glad I learned how to go into a shop in Eritrea and not worry about how long it was going to take to get what I needed and I'm glad I learned to sit for hours, drinking coffee or tea, talking or not talking, passing time, not killing it, not worried about what I should be accomplishing.
So, if you've thought of joining the Peace Corps, find out more. It's not perfect by any means (don't forget that it's part of a big bureaucracy, part of the gummint), but it's really one of the easiest ways to actually live and work in a remote location in an industrially undeveloped or developing country.
I just read an interesting article on PeaceCorpsOnline about the connection between corn farming and malaria; I quote: An Ethiopian colleague of Kebede had found that the larvae of the mosquito that carries malaria had a survival rate of 93 percent when it fed on maize pollen, as opposed to a survival rate of about 13 percent when it fed on other possible food sources. Furthermore, adult mosquitoes raised on maize pollen had uncharacteristically large wingspans and long life spans. Read the whole article here.