It's no big secret I have a bunch of radios in my truck. In fact one of my next posts will highlight what I have installed in my Mobile Antenna Farm.
While driving through the mountains on the Rimrocker Trail my APRS transmitter was happily sending out telemetry data every 5 minutes (because I was traveling less than 60 miles per hour) or every time I had a more than a 14 degree change in direction. Because of the range 2m has while in the mountains (Line of sight from 9,000 feet is a long way.) I actually have a pretty complete picture of where we traveled.
APRS isn't as perfect as plotting your own maps with an onboard GPS and Tracking software, but it's kind of neat to know that the family of one of the guys with us could fairly reliably track our progress through the Rocky Mountains.