I always keep a couple of road flares with me for starting a fire when everything is wet. A folding boat anchor can also be very useful if you get stuck with no trees nearby. Sometimes I bring a gortex bivy sack and a sleeping bag. I can compress them to about the size of a basketball. Some other things that I bring, but didn't see mentioned include parachute cord, hand and toe warmers, a life straw, and a waterproof boonie hat.