Thank you all for the replies --
The places I go to do not have cell towers. I'd be relying on satellite GPS only. I've looked into "Personal Locator Beacons" but they're pretty expensive. That's why I'm asking about the 8310!
John - you said: "There is also a 3rd party application for the BB that lets your GPS location be sent to a server where you can allow others to track your location."
What 3rd party application might that be?