Here’s a system I would use. Posting my geolocation along with text trip report updates.
Details on Gadling:
… allow adventurers to more effectively communicate from locations that are not covered by cell service.
The new device pairs one of DeLorme’s GPS units with SPOT’s next generation Satellite Communicator, to send custom message from the backcountry. The Earthmate wil have all the regular features you’d expect from a GPS, including base maps, in this case covering the entire world, navigation, electronic compass, and so on. But it will also wirelessly pair with the Communicator, allowing the user to type text messages and send them to friends and family back home via satellite. …
It’s designed so you can call for help from anywhere, should an emergency develop.
… it also lets the user to share tracking information and custom messages that can easily be interfaced with Twitter, Facebook, Geocaching.com, and SPOT’s own SPOTadventures.com. …
Pricing not available until the Earthmate PN-60w is made available later this Spring.
If you are interested, click through to the article – New device will let you text, twitter from remote places