Nearly every day I read an article about crypto currency stollen from somewhere. I think there will be huge business around offline wallets. What I'm thinking about, to create a plastic scratch card, which contains a private key QR code under a scratch able place, which you can free up when you want to use your crypto currency.
Why this good ?
*image source: www.buybitcoinworldwide.com/img/goodicons/wallet2.png
Because if you store the key offline, you can bring it to anywhere where you want to take.
Because it small factor, it can be put to your purse.
For saving, you can easily transfer money to it. A save which only accept deposit.
This is far better than physical safes, because you can check it from everywhere, and you can put inside more amount from anywhere, but you can put it on a safe physical place where no one able to access it.
When you need to transfer from one physical location to another, than it is only one card, and able to hold unlimited amount!
This is why this far better than physical gold!
https://www.rt.com/business/400063-bitcoin-blockchain-gold-trading/
And it is in safe until you don't want to use it!
I have plans to create these offline wallets available, with audited factory process, which can make more trust for wallets.
After a properly audited manufacturing procedure, it can be also used for Stock exchanges, to move their assets to these offline wallets as physical saving, which make them immune for break in. They can freeze the long term investments to these offline wallets, which makes them a trusted store, like a Bank for money.
Until the Quantum computers age start this will be a good solution store safely the crypto currencies which we have on our accounts.
After we have quantum computer safe crypto currencies, than these wallets will be much more safe.