Those are just paper wallets. I was thinking more of fixed amounts with the amount on the front to simplify it for non techies.
Ideally you wouldn't be able to send coins to the address and only redeem the whole amount but there'd be no incentive to do anything else anyway.
The point is making them usable as cash.
same idea. and amongst the 36 pages were discussions of a central service that held the private keys. so that the notes just held the public key for value verification. but most preferred the de-centralised method, which meant that holograms were placed over the privkey and any tampering would make the note void.
most people just use them like gift vouchers/cards. from on person to another. not true circulation just betwn 2 people, such as inside a birthday card to relatives.
but atleast if you search for bitcoin notes you will see your idea is not new. and has been poked and prodded for atlast 2 years