The other thread got me thinking about how I compartmentalize my tools at work and doing the same with my SHTF bag.

Here's what I'm thinking. Inside my Kelty Redwing 3100, a medium butt pack, with a Molle electronics pouch inside it. Last ditch stuff in the 6"x4"x4" pouch, like 1 disposable lighter, pocket knife, 10' of 550 cord, small compass, mini Fox 40 whistle, Starflash Ultra signal mirror, Inova Microlight, 1 contractor bag, 1 sandwich Ziplock, 1 quart Ziplock, 1 gallon Ziplock, 1 bottle of water purification tablets, basically the stuff you'd put in a medium tin.

In the 10 1/4" X 9 1/2" X 6 1/4" butt pack I was thinking my Cold Steel Tanto, a 32-ounce Nalgene, knife sharpener, 1 2400 Mainstay, my small FAK, the small pouch listed above, etc...

http://www.imsplus.com/molle-electronics-utility-pouch.html
http://www.imsplus.com/butt-pack-enhanced-.html

I've been kind of doing this already, as I carry my last ditch stuff in my Nalgene right now. But I like organization and not just having everything thrown in the big bag.

Any ideas on what would be best in which size bag?