I will be carrying a SPOT GPS tracking device I am borrowing from a friend (thank you Dan!). It is a small device I have mounted on my handlebars. It will send a position update directly to the SPOT satellite every 10 minutes and then it will update my position on a web site so everyone can see it. Here is a link to how the network works. And here is a link to the satellite global coverage map.
Finally, here is a link to my specific web page where you can follow my progress.
Another thing to know is that I can push a button on the SPOT and send a canned "Check-in" message. I will normally send a 'check-in' message when I am stopping for a while, like for a rest or meal or at the end of the day.