Me too, I've got a Raspberry Pi on order …I want an offline address generator (based on bitaddress.org), however I don't want to print stuff out. Instead, what I would like is to generate the private key and have it encrypted and displayed on screen as a QR code…then I want to snap a photo of it with my phone for backup purposes (and copy that photo to various online locations for backup).
As a further improvement, I would like a wallet that would sweep a specified amount of coins from an address to a new destination while sending change to a second address (which would be another offline generated wallet). That would provide a convenient means of taking just a specified amount out of an offline wallet while returning change to a newly generated offline wallet.
I'd be afraid of malware on my phone grabbing the QR codes and thus, stealing my keys. I'd rather use a simple non-network camera if I was going to take photos of QR codes. But then, how can you be sure of making backup copies of those without malware stealing those photos?
Here's how I use my Raspberry Pi to generate cold storage wallets.
...
Sorry to keep harping on this but this is exactly why I made Armory.
As far as I know, there is just no simpler, safer way to use offline wallets than using Armory. I use a 10-year-old laptop for the offline wallets, but the Raspberry Pi is the perfect compliment to Armory:
Setup offline wallet:(1) Generate Armory wallet on offline machine (Raspberry Pi)
(1a) Print off a paper-backup of the wallet: all coins can be recovered any time in the future with the 64-bytes on one sheet of paper (not encrypted)
(2) Click "Create Watching-Only Copy", import to online computer (no private keys)
(3) Online computer can now generate infinite number of payment addresses and monitor incoming transactions/payments
(4) Online computer only has public keys, wallet cannot be compromised.
Even if other solutions/methods succeed in the above, nothing is easier than Armory for spending those coins:(1) With the watching-only wallet, click "Prepare Offline Transaction"
(2) Fill out transaction exactly as you would with a regular wallet. It will ask you to save it to a USB key.
(3) Take USB to offline computer and go to "Sign Offline Transactions"
(4) Review transaction, sign it, it will add the signature(s) to the transaction on the USB key
(5) Take back to online computer and broadcast
You can generate infinite addresses/public keys, and monitor incoming transactions just as you would a full wallet. And it takes less than 60 seconds to execute a transaction (once you have some practice). Quite a bargain for the peace of mind that your private keys have never been near an internet connection. Also, the wallets are encrypted using AES and scrypt-based key-strengthening. And your single paper-backup protects you for forever (minus imported private keys).
Armory is technically still in alpha, but it's due to setup and usability concerns, not security or stability. In the 8 months since Armory has been public, and with 1,500 downloads per month, still no reports of anyone ever losing money with it. Some users have reported using Armory with 10K+ BTC. It will be beta soon, but most users treat is as beta+ already. (P.S. - of course Armory is OSS and comes with the usual "I am not liable for anything" clauses, I'm just commenting on its track record)
The point of this story:(1) If you want cold storage, look into Armory
(2) If you want cold storage, but don't want to deal with laptops, RaspberryPi will soon be your answer
(3) Someone will soon be posting instructions for using it on RPi