I had the good fortune to travel the world for nine months back in 2001, stopping in many third-world areas. I did two things to keep myself healthy, and give my family peace of mind:

1) I visited a travel medicine clinic at least six weeks before leaving. This gave them ample opportunity to make sure I had all necessary inoculations on board. They also gave me scrips for anti-biotics (cipro) and anti-malarials that might have come in handy.

2) I purchased a travel medical policy. It was really cheap, something like $250 for the whole time I was away. I would have had to pay out of pocket for any services, and get reimbursed. It also included $100,000 of evacuation coverage, and repatriation of my remains if anything really bad happened.

I had only three real health issues the whole time I was away: Travelers diarrhea in Senegal and Nepal, which the cipro took care of, and a moderate case of HAPE just below Mt. Everest Basecamp. In the latter case, I was treated by the Himalayan Rescue Association High-altitude Medical Clinic and given all sorts of drugs and advice, for the grand total of $25. I also bought a cool T-shirt with the clinic's logo! While I did not need it in the end, it was comforting to know that had a helicopter been needed to get me to lower altitude, the cost would have been covered.

I considered the insurance to be inexpensive and well worth it. I found my policy through my travel agent who specialized in esoteric travel, but using Google so I'm sure you could do the same.