Check out this Zen Habits post:
The basic idea is that if you had to pack up your most precious belongings in the trunk of your car, which belongings would you pick? I thought about this for a while and it was easier than I thought. It inspired me to put a fireproof safe on my shopping list, do a little house cleaning and think about getting my favorite books/movies in digital format on my computer. Here is what I came up with.
On my body:
Wallet, iPhone, wits and sense of humor
In my trunk:
Laptop Bag (laptop, cables, camera, external hard drive)
CD wallet of software
Important documents – Passport, Birth Certificate, etc.
One box of mementos
Tai Chi sword
First Aid Kit, Multi-Tool, Knives
Backpack, Shoes, Clothes & toiletries
Water & snacks
Old Journal, Notebook & pens/pencils
Books: Integral Life Practice, Enders Game, Bible, How to Be an Adult, Walden, How to think like Leonardo da Vinci