Be wary of nuts. I used to chuck everything from the bottoms of dried fruit and nut jars left over from Christmas baking into a ziplock bag at the beginning of the season, leave it in the pack and top it up from time to time. I found out the hard way that nuts can go off and give you the runs at the most inconvenient times.
I've been off GORP ever since, which is a shame as I used to enjoy the complete lack of recipe and the random result as different things settled to the bottom of the bag. No handful ever tasted the same as the preceding one. I remember that cooking chocolate chips were good in the mix.
Perhaps the recipes on this thread will inspire me to give GORP another try.