In 2 weeks I'm going to Jackson Hole, Wyoming for some snowboarding, but on one of the days I'll be taking a snowmobile excursion into the mountains to take some photos. I just got a Lowepro backpack for the occasion and am trying to think of everything I should pack. Right now all I can think of are the essentials: camera, backup lenses, charger, my old point and shoot camera (just in case), and a microfiber cloth. I think that's really all I need, but can't help but think that I'm missing something. What do you guys/girls carry with you?