There are other posts on here that describe a better method for setting up a vault wallet.
The BEST method (in my opinion) is to create your "vault wallet" when never connected to the internet, and never have it hit a hard disk. In summary, if you download LinuxCoin, and put it on a CD or USB key, and boot from that, you will have a memory-resident version of Linux with the Bitcoin software.
Then start the Bitcoin client which creates a wallet file. Terminate the program. Put the wallet file on the USB drive. Put it on a few CDs. And write down the public key (the Bitcoin Address), or put the public key on a SEPARATE usb drive that you WILL allow to touch an internet-connected device. Shutdown LinuxCoin, and your wallet file is gone, except for the CDs and USB drives. NEVER let them touch an internet-connected PC (until you're ready to cash in your savings).
At this point, you have a wallet that has NEVER been touched by the internet. Never been on a hard drive. It's pure. Toss that USB and CDs in a real bank vault (or two, separated by 100 miles), and you're golden. Any time you want to move money to your savings account, simply send it to that public key Bitcoin Address. Easy-peasy.
Now.. will Grandpa ever do that?
No, but Grandpa WILL buy a Savings Account kit from a trusted party. The kit has 1 USB drive, a couple of CDs, and a public key.