I don't keep one pre-packed but my packing list is geared towards evacuation in case of natural disaster (Hurricane Isaak is approaching as we speak) Therefore I include the following:
-Nonperishable food or rations
-A non-electric can opener (a P38, or SAK is fine)
-Blanket or sleeping bag
-Prescription meds
-Extra clothing
-Flashlight
-Battery powered radio
-Cash (important because during power outages bank cards won't work)
-Vital phone numbers (relatives, insurance agents, Dr., etc)
-Important papers (Deeds, Insurance cards, etc.)
-Games for the kids (if you ever spend time in a hurricane shelter with kids you'll know why)
-Extra batteries (for radio, phone, flashlight, EVERYTHING you have that uses batteriies)
-Dog food and supplies
-Dogs' shot records
Other preparations:
-Fill all gas tanks before the storm (and get enough for emergency generator for a week)
-Collect enough water for at least one gallon per person, per day for at least 3 days (3 gallons per person, per day, for a week would be better) and enough water for the dogs