Any GPS Device That Does Both Directions and Caching? in GPS technology and devices Posted February 14, 2012 "Pick the right tool for the job" guidance is to buy two devices. For geocaching and many other outdoor uses I want pocketable, long battery run-time, weatherproof, rugged, accurate to within a couple of metres. For car nav I want big screen, touch and/or voice controls, turn-by-turn spoken directions, accurate to within a city block, maybe an FM or cellular data feed of traffic conditions and alerts. Two different jobs, two different units. At the moment for me that's an eTrex 20 for the outdoors and an iPhone for everything else.