This is my first experience with satellite phones but so far its been pretty easy. I bought a used Qualcomm GSP 1600 (pretty cheap on ol’ ebay) and went through GlobalStar for the service.
The contract (Evolution Plan) is fairly cheap at about 35$ a month with a month to month contract. Currently Globalstar is in the process of changing over some of their satellite technology, adding more satellites, and improving service. However, for the time being their are significant gaps in coverage.
Using their Satellite Availability Tool for northern Brazil and the middle of the Amazon I see that throughout the day most calls will have to be limited to about 8-11 min or so before they are dropped. That means during any given call I may lose the signal fairly frequently. However, I plan to keep conversation to a minimum as roaming fees (between 1.40$ – 1.99$/min) apply in this remote region.
Also, I can’t receive calls. Kind of a bummer there but the peace of mind with having the ability to call someone from nearly anywhere on the planet (with the exception of some areas in the middle of the ocean) outweighs the annoyance of dropped calls.