I second the SPOT tracker, I've used it for years, and am very happy. My wife will save off an image of where I flew for week long trips.
Extra benefit is communication home from anywhere on earth, at no additional cost, as long as you work out the code with the limited messaging function. I brief my passengers, mostly my 11 year old daughter, as to how to use the message functions, and emergency buttons, so they can help themselves, if I cannot help them after a crash.