Steve: I think you asked this on one of my comment forms, but I can't seem to find where that was. (I'm having minor issues with my comment forms, but will fix.) Sorry for the delay.
1. I used Kaiser (a California-based HMO). It was about $150-200/month. If something bad happened while I was away from California, then I would pay for it, submit the receipts, and they would reimburse me. I never had to use it, but I suppose it should work.
2. Get specific international travel insurance. This is a separate, private insurance, which can be expensive, especially if you want them to cover you going to extreme places or doing extreme activities (which I tend to do!). It's about $250-500, although I didn't shop around too hard. The advantage is that they specialize in international travel, so presumably they should have less paper work and hassles. But again, I've never had to use it.
3. No insurance! I've done this for few years too! The idea is that if you're paying $200/month, then that's $2,400/yr. If you break your arm, most countries will treat you and even if you have to pay out of pocket, the fee may be less than $2,400, especially if you're going to the dentist once a year or getting anti-biotics, or whatever minor ailment. It's a risky strategy. But if you're poor, you may have no other choice. Frankly, I don't think the risk is as bad as most people think. Finally, medical insurance companies will (understandably) do their best not to pay more or anything. That's their job. So if you broke your leg climbing a peak in Africa, then they may say that it's not part of your coverage.
Most importantly, eat well, exercise everyday, and sleep soundly. That's the best insurance around.