For those who have babies and young children. I saw this on another site.
1) disposable diapers are the best for this situation. Don't like to think about it, but when a cloth diaper gets wet, it is wet everywhere. Disposable diaper gets wet, it is dry to the kid's skin until it reaches saturation point, which is several cycles. This is why when you potty-train your kids, you either let them run around naked (and follow them like you do a puppy), OR you put them in cloth and let them get the 'feedback'. Anyway, you need to get on the disposable train for the 72 hour pack.
2) I'd keep a few cloth ones in case you run out. If you end up in a fedgov shelter, you may not get diapers. If you stay out of the fedgov, you surely won't be getting diapers
3) clean water is your friend. Get a great filter like the ceramic/silver used in Katadyn stuff. Bleach is a good double-use item: makes clean water, and cleans your cloth diapers and other stuff
4) put that diaper stuff in momma's pack. It'll end up there anyway
5) find out if your kid is allergic/sensitive to the brand of diapers you think you are packing. My kids aren't allergic to anything (as far as we know), but they all got rashes from Pampers. Non-scented stuff (huggies for us) seemed to work best
6) skin stuff is going to be important: desitin (sp?) and Lansinoh are beautiful things when you need them
7) besides what you carry in a pack, get a roller bag. Put some food and clean water in there, as well as sanitation stuff in a five-gallon bucket: alcohol hand-wash, garbage bags, tp, a folding shovel, and some lye or other chemical for dealing with poop. Kids cheapo athletic bags have roller wheels these days, and will fit a five gallon bucket perfectly. I don't know if you saw what the bathrooms looked like at the Superdome, but I wouldn't send my wife in one of those places, and I'd rather avoid it myself. Line the five-gallon bucket with garbage bag, use, cover with lye, put lid on. When you can't take it anymore, take your folding shovel and get rid of that abomination. Disposable diapers can go right in. Get out the next bag to line the bucket, and you are GTG.
Babies are hard to deal with since they can't walk. I'm so grateful that mine can all self-propel these days. Roller bag will be doubly important, since your wife's pack will rest on top (strap?) since she will have a baby back-pack if you have to walk somewhere.
Here are some instructions for preparing single use packs of formula. Might be something to consider.
http://www.epinions.com/review/Tilia_FoodSaver_Bags_8in_wide_22_long_01024/content_337155427972
