This thread starts with a detailed description of what happens when you push the SOS button on a SPOT messenger. Apparently, many long-distance motorcyclists carry SPOTs for tracking and emergencies:
http://www.bayarearidersforum.com/forums/showthread.php?t=431684
With a detailed followup:
http://www.bayarearidersforum.com/forums/showpost.php?p=7987865&postcount=47
Some interesting parts:
“Immediately after pressing the button, all of us (~20 people at that point) all looked at each other and asked, “OK, what now?” No idea. We didn’t know if Spot/GEOS got the message, if they’d respond, who would respond, when they’d get here…”
“My wife had to endure 3 hours of not knowing if I was alive/dead. She was on the road headed to Monterey hoping to find me in the hospital by the time I finally got cell reception and was able to call her. To say that she’s traumatized by the event is definitely an understatement. She advises that I’m now only allowed to ride to the Starbucks and back for the foreseeable future”
The rest of the thread has some interesting comments, too:
“It’s worth pointing out the GEOS Alliance rescue service is the defacto standard in the industry. Whether you go with a Spot, a DeLorme, or a $1,400 Iridium sat phone… the SOS button on all of those is routed to GEOS.”

