What a classy backpacker carries: Snowpeak’s Titanium Flask ($160, 2.7 oz., snowpeak.com). Yeah, it costs more than a case of whisky, but its sleek, indestructible frame will impress your great-grandchildren. What a practical hiker picks: GSI Outdoors’ 10 fl. oz. Flask ($8, 3.6 oz., gsioutdoors.com). Stash this BPA-free plastic container in your pack and pour servings into the shot-sized lid.