I just read through this whole thread and it seems to me parts of it went a little bit off topic. <img src="/images/graemlins/smile.gif" alt="" />

I'm willing to guess that 99.9% of us who carry some form of knife/tool will never need it for self-defense. I don't generally walk out of the house without something bladed in my pocket, but I think the prospect of using it to defend myself is pretty remote. (And besides, if I'm out in the middle of the night, I generally bring the dog and her growls clear sidewalks... <img src="/images/graemlins/grin.gif" alt="" />)

Since this is the original anti-hype survival site, more likely scenarios for me are the unfortunate things that happen in cities. For anything more than a walk in the woods, I take a fully stocked pack, but around town, if it's not in my pocket or on my belt, it's not with me. So, I almost always carry a Leatherman, and more often than not, it's a Leatherman Juice.

I'm no expert on any of this, but here's my two cents:

1) Serrated blades make quick work of seatbelts and stuck clothing. I'm not worried about my own seatbelt, I'm thinking of someone else's here.
2) Screwdrivers can be your best friend if you're locked in somewhere
3) Pliers can be used to twist and snap metal. They can be used to pry things in places blades would snap.
4) Scissors and everything else are icing on the cake

I happen to think that the single most important always-carry-item in a city is a flashlight. Blackouts in the interiors or basements of very large office buildings really suck without some form of personal illumination. My experience is that most of those emergency lighting systems simply do not work.