Here's my situation. I carry a pretty extensive set of survival stuff in my car. I have a pretty comprehensive survival kit packed in a fairly generic-looking, non-tacticool backpack, plus other items like basic tools, both repair and rescue type, firearm. Most of my travels are in semi-rural areas with lots of woods, etc., so my survival pack is somewhat biased toward "wilderness" rather than "urban" survival. I'm in the disaster response business, so I've acquired various survival/disaster related training, as well as tactical/defensive training.

But sometimes I travel to the big city, sometimes by my car, but sometimes by airline, which limits what and how much stuff I can bring. So my questions are, what should I carry in a small air-travel friendly urban survival kit; what knowledge, skills or techniques should I a acquire; and what should my strategy or thinking include beyond the basics or obvious things; in the event of urban emergencies like widespread civil unrest or power outages, or any other advice you'd care to offer for when I am in an unfamiliar major city?