Perhaps the key is to set things up so that you are never totally dependent upon just one technique or gadget to get you back home. Somewhat analogous to the redundant fire starting items that most of us seem to carry. I believe that many of us learned decent map reading and orientation skills before GPS receivers came along, so that GPS technology is an added bonus.

I have seen GPS units fail, but they were early units, 1991 or so, and basically Stone Age relics compared to what is out there now. Finding your way through the woods is pretty fundamental to a successful trip, and probably one can never have too much expertise in this area.

One of the things to realize is that any of these tools can mislead you. Maps, even the USGS topos, can be inaccurate or out of date, compasses can be off because of local variation (ore deposits, belt buckles, or your iron-rich diet). GPS receivers can lose battery power, provide a bad fix because of poor satellite position or distortion of signals from various causes (deep canyons). Unfortunately, this means we have to think and maintain awareness...

One thing I do to deal with loss of battery power is to use common batteries in my lights and electronic gadgets. This means I might someday have to choose between knowing where i am or seeing where to go....