Caught this info on a local radio station the other day...
Basically, if you are a member of this group and are more than 150 miles from your home (including overseas/world wide!) and have an injury, they will come get you and fly you to the hospital of your choice.
I suppose if I were going to hike some foreign trail, the fee is only nominal considering what could happen.
http://www.airmed.com/amMain/main.asp