Cool, thanx. I'm glad to see that there are a few options for off-road gps in this world. In fact I would like to list some of the ones that I found in my search below. I'll also provide links to the software's website.
1. Topo 7.0 by DeLorme - I really like the "geo-tagging" feature for classifying photos. Cost 100 bucks, and you have to pay for the maps you want, but it comes with a free 100 dollar credit for downloading your first maps. Could easily end up being really expensive if you like to travel.
http://shop.delorme.com/OA_HTML/DELi...minisite=10020
2. OziExplorer by Des Newman - Has some interesting features, and seems to be the crowd favorite. (And may be so for good reason.) Also, appears to be the most cost effective. And from what I understand many maps can be downloaded for free.
http://www.oziexplorer.com/
3. Terrain Navigator by Maptech - Appears to be the most advanced software for this sort of thing, however, also the priciest at around $100 bucks per state! Ouch! And thats for the basic version. But my friends father has this and he can do some really cool stuff with it, he mostly uses it for river trips.
http://www.maptech.com/land/terrainnavigator/index.cfm
4. Global Tracker by Fugawi - At $135 it comes in first place for up front cost. Appears to be a pretty straight forward program with a broad range of compatability for different types of maps. Also comes with the software for your PDA or smart phone. And for any one who has a stack of paper maps in the closet, you can scan them in and use them to!
http://www.fugawi.com/web/products/f..._navigator.htm
Those are the three I have found thus far that could be used for Offroading, using the topography and trail mapping features of these programs would help you get around the mountain in style (If you ask me, having to back up down a trail because you didn't know there was a climb ahead that your vehicle couldn't handle is pretty sad, thats where the topo software would come in handy.)
Anyway, if you find any other programs, or have some more info feel free to throw it in.