We don't camp in the cold to much but in the early or late season when you just need a little extra heat in the morning or late evening we needed something. Until now we used a couple of small electric space heaters but we were out of luck if we were anywhere without hookups or boon docking out in the hills. I looked for a long time trying to find something that had some decorative style to it and still lightweight.
I really only found two choices in heaters, we chose the cozy cabin heater from http://www.go2marine.com/product/83100F/cozy-cabin-heater-propane-boat-heater.html
The other option we looked at was a dickinson fireplace: