Interestingly enough....to add a few cents to the convo, my Father bought a new 08 Camry. I was looking through the book and it's got a "Personal Locator Beacon" option you can add on at any time. It apparently ties into a few sensors on the car in the airbag system and goes on automatically if you crash or flip or the shocks loose compression (Off the road). Seems neat.
You might post more information on this if you get it. I could not find a reference on Toyota's web site.
Toyota has had GM's OnStar for a while under the name LexusLink. There's no PLB; the car has an integrated cell phone (you can't use it for making phone calls; it's for the car's use) and when the airbags deploy or other criteria are met it calls LexusLink/OnStar via that cell phone and sends event information including the most recent location from the Navigation/GPS system. Neat but no PLB - if there's no cell coverage too bad.
And before singing too many praises of foreign manufacturers over American:
The original OnStar scheme used an analog cell phone system for improved coverage. Then the FCC killed analog cell service in 2002, effective 1/1/2008 IIRC.
GM offers people with older GM cars an upgrade to a digital cell system so their safety gear works as it did when purchased.
Lexus told my mom to buy a new car, or they'd be willing to rip out the LexusLink system free (i.e., remove all of that safety gear).