As I write this, hundreds of thousands of folks are evacuating their homes on the East Coast in anticipation of Hurricane Irene making landfall, or at least a close fly-by in the next few days.
One thing that makes evacuation a lot easier is being prepared to simply grab an evac kit, throw it in the car, and in 30 seconds you're gone. If you have to slow down to gather up survival supplies, look for a way to carry them, and figure out how much of this and that you're going to need, the whole process gets mired down and costs precious time.
Even if you're evacuating to a relative's or friend's house several hours distant (a much nicer idea than evacuating to a FEMA refugee camp), you still need to be prepared with all your own personal supplies. You don't want to have to borrow someone else's toothbrush or underwear, if you know what I mean.
Everyone, whether they live in a hurricane (or any other kind of disaster-prone) zone or not, should have their own personal evacuation kit already prepared and ready to grab and go. The kit should have everything to meet your basic needs for at least 72 hours (longer is better).
The concept is that after that much time, life will probably return to normal and you'll be able to go back home. However, that may not be the case. Sometimes there's nothing to go back to where wildfires sweep through communities, or earthquakes knock everything down, or tornados obliterate whole neighborhoods, or floods wash everything away. That's when the evac kit might need to keep you going for months.
Think about that, and plan your kit accordingly.