BTC Vault is a Linux Live-CD that should help to store and handle bitcoins securely.
Also, this may need clarification:
With the electrum bitcoin client it is enough to backup the master key called "seed":
You can print it out and store it in a safe place.
You can encrypt it and store it on another safe computer or on a usb stick.
You can use steganography to hide it in an image file.
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http://dswd.github.com/btcvault/security.htmlThe problem is if someone imports a private key to Electrum, that Electrum wallet still needs to be backed up -- just having the seed is not sufficient.