Along the same lines, I use a jansport backpack for school and weekend trips and have used it every day for about 4 years now, and it's almost as good as new. It has an outside storage space to stuff a jacket, and I have clipped a waist pack to that, along with a jacket if I'm wearing short sleeves. The waistpack is the same color blue as my backpack, (actually, so is the jacket, I guess i like that color)so if you don't look too closely it appears to be part of the pack. I'm still working on the kit, and when I have it to where I'm happy with it I plan to post the contents here for review, but i was suprised at how much I could fit in there. It has a small outside pocket where I keep a few things I could need in a non emergency. When I'm not taking my pack, I unclip the waistpack and throw it in my Jeep to augment that kit.
Hope this helps,

Chris.