I use the Delorme InReach. Absolutely love it. I haven't been too many places where cell phones don't work but every time I have so far the GPS communication works great. A lot of the year the account sits at the lowest level to just keep it active but it is super quick to jump it back up to...
EvlDave has the best walkthroughs I find and he has a great walkthrough for a dual battery setup.
http://forum.expeditionportal.com/threads/77503-How-to-make-a-cheap-isolated-dual-battery-setup-for-50
Be sure to follow every step, especially Step 1!
The SPOT communicator failed me when I was in Africa. Having the two way messaging is so much better. Price wise it is a more expensive service plan but you can just bump your plan down to very little to carry it through the months that you do not need it. Last minute trip? Just pop online and...
As long as you have a buddy willing to call AAA for you with your information you should be able to get roadside service. Usually they just ask for the car details and location and I could send that via text message to friends or family and they can arrange the tow. Over the price of the...