lol.. well there goes my theory that casascius was throwing out this little puzzle to demonstrate how easy and convenient it is to import the keys from paper wallets!
That's just it, it's not yet easy.
I was mainly trying to show that Bitcoins can be hidden in short amounts of plain text. Any text will do, as long as it's not too short that it can be guessed by brute force.
An entire wallet could be generated from a short amount of plain text as well - simply by adding a counter onto the end of the string. That's been proposed as a "deterministic wallet". If done that way, one would never need to back it up, as long as they kept the original string safe and secure.