I'll second what UPHunter08 said about overheating. You don't want to sweat even a little before you settle in and have to sit still. It will make you colder later on.
As for storage, I use a camo fanny pack for carrying what little extra gear I need. I have pulled out my rain pancho and draped it over the entire climber to make a tent during a shower. I love being out there ready to shoot when the rain stops. I take the fanny pack off and clip it to the right side of the seat section when going up and down. Sometimes I leave it there while I'm sitting too. On Sunday I shot this bad boy from my Summit Viper.
