There is another thread on Globalstar and their problems that I have been following. The company's stock is down over 70% and is indicative of their problems with deteriorating satellites.
I have never used the phones, but I recently got a SPOT messenger
and I don't know why, but it works pretty well around here. It operates on the Globalstar Satellite system to relay your GPS position but apparently doesn't need much to get the signal through.
If I leave it on the "track-progress mode" it will update a position about every 10 minutes. It misses a few reports, but more or less it tracks your progress. It is a cheap way for friends and family to go to your "findmespot" page and see where you have been. You can let people know you are safe without having to deal with their annoying phone calls.
The "track-progress" has to be reset every 24 hours, which you have to remember to do. There is also a "check-in" mode and it also works pretty much as advertised. If you push the OK button it will send a single email to your list of contacts that says you are OK and they can view it on Google Maps.
It's a pretty cool little gadget and for me is like an extra EPIRB - not a substitute for one, but another safety option. There is a 911 button that sends a call for help to a GEOS center.
I recently told my 17 year old son that I had put it in the trunk of his car and would be watching to see if he veered from his innocent sounding travel plans. He looked for it and couldn't find it, so he assumed it was hidden in there somewhere. I'm not sure if it would work in a trunk, but the threat seems fairly effective.