My Mountain Hardwear hiking pants have a zippered compartment in the right pocket, I always put a Fenix 1xAA, Ritter MK1 knife, and matches in a waterproof aluminum case there. I carry a whistle on paracord around my neck, with a P-38 can opener attached (for luck, and in case I encounter a nasty can of beans on the trail). That's how I roll - I once forgot the whistle and nearly turned around at the TH and went home, but found a spare whistle in my pack so I put that in my pocket. Its funny how repetition shapes our lives - I feel naked without pocketing these things on the shortest day hike, and more than likely will turn around if any of them are missing. OCD?