I did a voulunteer mission with my church to Thailand. We built houses and taught English. It was a excellent auxillerating experience I couldn't forget and smiles of the less fortunate people. I would highly recommend it if you do speak the native language or not.
I taught business English for 8 months in Argentina. Loved the work, loved my students, but hated being screwed around with by the various agencies that found me work. The pay and hours were rubbish. Maybe if I was outside of the city where the cost of living is a little lower... but then there wouldn't be awesome business people for me to teach. I did know one guy who got a job training at IBM there before he even got into the country, and that sounded more rewarding/consistent. I, on the other hand, just plunged headfirst into the place, and, while it was exactly the cultural experience I wanted, it was probably a tad more draining on my resources than I would have liked. If it's money and security you're after, you want Taiwan or South Korea.
I taught English in Korea for three years and will be moving back to Korea in a few months. American desk jobs just can't compare to living in another country right now...especially since I'm still in my 20's.