I have been asked by several people about HAM radio and its use offroad. In years past, CB radio has been used, and more recently, we as a club have been using FRS radios for trail communications. The limitation to FRS is the short distance available due to the frequency used, as well as the limitations of most "bubble pack" radios. This past weekend, I heard that the San Diego Land Rover Club has moved to almost exclusively use HAM radio for trail communications, allowing for better communications over longer distances. It opens up the ability to use repeaters in many places, thereby extending one's range by many miles, and with some repeaters, worldwide.
Expedition Portal just published a great article on the use of HAM radios for overland offroad travel.
Link to Expedition Portal HAM article
After our LandOps adventure, some of the drivers indicated an interest in obtaining a HAM license, and the use of HAM for offroad, or as a hobby. I'm glad to answer questions about HAM, and would encourage you to explore obtaining your license. For around $100, one can get a basic radio which can, under the right conditions, reach miles away, and improve your safety while offroad. Feel free to drop me a PM for more info.