We don't need too many things to survive (my kids would be fine with an iPod and a can of Rockstar). For a few dollars, you can have what you need sitting on your shelf or in the trunk of your car, ready to deploy at any minute. These emergency kits provide you peace of mind.
If you live in hurricane, tornado, flood or earthquake country you should have an emergency kit to get you through at least 24 hours with you at all times. At home, you should have enough emergency supplies for three full days.
For all of these emergency kits, I recommend adding extra water, and you'll have to supply your own iPod.

Photo Courtesy of PriceGrabberA compact single person pack, small enough for keeping in the car. Put this in the trunk for a quick getaway in case orders to evacuate come faster than expected. Not much here to wet your whistle, so remember to add a few bottles of water.

Photo Courtesy of PriceGrabberThree days' worth of supplies for a single person with a bigger bag. More supplies than the fanny pack with room to add personal items (medicines, wallets, glasses, etc).

Photo Courtesy of PriceGrabberJust enough stuff for one person, one day. This is the quintessential bare minimum to keep in a car just in case you get caught in a jam -- traffic or otherwise.

Photo Courtesy of PriceGrabberThis backpack has enough supplies to keep two people going for three days. Of course, it could always keep one person good for six days or six people for one day -- you get the idea. Another good option for the trunk.

Photo Courtesy of PriceGrabberA bucket of stuff for the family and a bucket of stuff for the family pet. This disaster kit contains enough supplies to keep you going three days (although I can't vouch for the flavor of the energy bars).