I'll throw in my two cents here. I've carried bags of one kind or another for probably 20 years, at least. The one I like the best and the one I carry the most is my courier bag from Courier Ware. Check them out at www.courierwareusa.com. I have their size small and I'm constantly amazed by the amount of stuff I'm able to carry in it. In fact, I've been able to put so much stuff in it that I could barely lift it! We have a diaper bag that we use for the kids, but it usually stays in the car. When we get out and walk around somewhere I usually stuff a couple of diapers - bulky cloth diapers - in there with the rest of my things and we're good to go.

As for Indy bags (the Mk VII gas mask bag), I've had a couple that I bought years ago at Colonel Bubbies in Galveston for about $12 each. (When I saw what originals are going for now my eyes bugged out of my head!) They're good for small day bags. I still use the one I have left for when I want to carry my wallet, my small day planner, a few pens and pencils, a steno pad, a small rangefinder camera, and my reading glasses. Probably wouldn't work very well as a diaper bag, though. At least not for me.

Leather bags look really cool. BUT...leather is heavy, and a large leather bag is going to be fairly hefty even empty. That's something to consider if you're going to be hauling it around on your shoulder all day. My wife bought a great leather purse from a custom bootmaker, hand crafted to her specifications. It's maybe a couple of inches bigger than an Indy bag. After carrying it for a year she hates it. It's too heavy for her, even with only a little bit of stuff in it.

~Ken