I routinley carry a Hand Held Satellite phone as part of my Survival Kit . I find that as I do a lot of charter flights outside of Mobile phone range ( you call them Cell phones ), within and outside Australia, carrying a Sat phone was a plus ( mine has international roaming as part of it's features ) . As I also carry a very good hand held GPS receiver, that and the Sat phone are an excellent back up to the GPS enabled 406 Mhz PLB, which is also carried as part of my 4 person Survival kit. My kit also carries a Mobile phone, apart from the one that I carry on my person, as well as a hand held aircraft radio, and a hand held UHF CB radio. My kit as I said is based around equippiing 4 people for 3 days ( tools/shelter/food,cooking / signalling / protection). The protection component includes a 9MM Hand gun, but thats another story.

Who do you call on a Sat phone for help? A family member or friend, give them your GPS, and they call whatever emergency services serves your area?

Is there an "International Emergency Number" that could route local help to you?

Seems like you are well equipped. A belated welcome to the group, BTW.

I can call the area that I am flying overs Civil Aviation Authority/ Emergency Management Department. I have manuals, charts etc ... for all the area's that I operate in ( Australia/ New Zeakland / South East Asia, even the US,Canada, South Africa to name a few ). My main contact is our Charter company emergency contact number. They / we keep a database of Emergency contact number for all the areas we operate in. As a last resort I can contact the company that we are chartered by.