I love the APRS stuff. I will confess I'm kind of a nerd when it comes to this stuff.
I set this up initially for a couple reasons. 1. my wife doesn't enjoy this 'overlanding' thing like I do, and it gives her peace of mind to know where I am. I'm cool with that. It's also a safety device. In the event of an emergency, it's a way for the 'good guys' to come find me.
2. I don't have the best sense of direction, and I like to review my routes after the trip.
I've got three setups: an "RTG" setup from Byonics.com that is literally a plug and play setup. the second is a TNC, GPS puck and antenna plugged into an extra 2m radio installed in the rear of the truck. that way I always have a full power backup 2m. I only transmit my APRS signal at 5w or 10w.
third is integrated into my Yaesu 8GR HT. It's with this setup I can get even more out of APRS. Kurt(CruiserOutfitters) and I were messing with APRS Text messages, too. Since I can "see" him on my radio, I can send text messages from my radio to his. Additionally, with his Kenwood, he can see where I am in relation to his location (bearing and distance). if you have to meet up with another group in Utah "somewhere" it can be really cool. We used it for him to find our camp at dark one night.
With "openaprs" website, you can register and send APRS messages to folks through the site.
It's cool. post up more questions...and daveindenver can enlighten us even more.