I see references to printing out your wallet.dat all over the place and I really like that idea. But, when I open up my wallet.dat file in word pad it is 200+ pages long. Am I missing something here?
Sorry, yes, I have mentioned a few times that a printed copy of wallet.dat would be attractive to me. But let me explain:
First, the valuable part of wallet.dat is the key pairs.
Second, Bitcoin creates 100 Bitcoin Addresses to start with, and each time you perform a transaction, your wallet gets a little bigger. You'll create more keypairs, and therefore more size.
What I was trying to say is that you can create a virgin wallet, and print the important parts of THAT. Specifically, the key pairs necessary to reactivate ONE bitcoin Address (not 100).
That set of information is relatively small - I believe significantly less than 1000 characters. It could easily be printed and stored on one page. Even a virgin wallet file with the 100 key pairs is only about 16K.
My logic with this was to create a "vault" for your long term storage. It would be used for deposit only, until someday when you want to retrieve it all. The paper would be a fail-safe, if all media failed (imagine you store your wallet.dat file in a safe deposit box, and the renter next to you stores a large magnet!) Paper has some advantages.
The next question is, though, what do you do with this paper in the event you need to recover. I believe it would be relatively trivial to write a program to recreate a valid wallet file given the piece of paper, but I haven't proven that yet. I also believe that if I had 100K tied up in my ability to perform that task, I'd get it done! (especially since the Bitcoin software is open source, and the file format is documented.)
Here's all the stuff that's in a "loaded" wallet.dat file. That's why I think you want a "virgin" file (and you really only need 1 address's keypairs):
your keypairs for each addresses
transactions done from/to your addresses
user preferences
default key
reserve keys
accounts
a version number
Key pool
See why it gets huge?