I could read these types of threads all day long!
Having lived NYC through a number of emergencies - the 2003 blackout and 9/11 being the most significant - I have explored this topic rather thoroughly and developed a pretty realistic, yet EDCable, kit over the years.
When I leave my apartment, I always have a bob "kit" with me that can just get thrown in any bag I carry. This is all in a Spec Ops PackRat Organizer and my edc bags are either a Kifaru E&E, Tom Bihn Cafe Bag or my Orvis Overnight Briefcase.
Urban edc and bob composition is a very different animal than one suited for the county in my opinion. Living in NYC, if there is a disaster or emergency, there are always resources around and access to food, water and medical supplies - there are convenience stores and pharmacies on every block.
With that said, in the city we don't usually have a car to dump a huge bag in and, as this is the case, one really needs to carry with them on person what they'd need in an emergency as it is unlikely one will be able to get back to their apartment to grab the bob or go bag. IMHO one of my most important things I carry are a bunch of lights because so far living in NYC this has been the most important emergency item - during the blackout I was on a subway and had to walk the tracks. I spend about 2 hours a day underground on the subways so getting stuck there is my biggest concern.
The contents of my bag are:
Surefire LX2 + F04 diffuser
Glotoob Lithium - Green
Petzl E+lite headlamp (to be replaced w Surefire Minimus)
Keep2Go tube with 4 Surefire CR123s
3 cheapo fauxtons clipped around
3 pair contact lenses
Eyeglasses
Suunto Compass
Bandanna
Protein Bar
Space Blanket
County Comm widgy bar
Spare set of keys
Bic Mini lighter
mini nail clippers
$300 cash in assorted pills
Benchmade Rescue Hook
Assorted Pens, Sharpie, Fisher Bullet Space Pen
Rat Cutlery RC3 or Fehrman Peacemaker
Leatherman Wave
Mini bottle of hand sanitizer (clipped outsude)
Paracord - 25 feet
CountyComm GP4L shortwave radio
Iphone charger
Moleskin small writing pad
Altoid Tin FAK
In my bag I also keep a Klean Kanteen 27oz wide mouth and a pair of leather work gloves.
When I leave the city there are other things I add as well as a more comprehensive FAK.