For daytrips I’ll take my iPhone and my Garmin GPS. For camping I’d have a headlamp and a handheld with variable output, and extra lithium primary cells for both. I suppose a decent weather radio would be a good idea. All I have is an old radio shack cube powered by a 9V battery. A battery to charge the iPhone would be smart for longer trips. Oh, and my D-cell air bed inflator! If I were just using a thermarest I’d drop the inflator.