The Wallet of Elrond
Peek a folded billet, using a your own wallet as the peek device!
– They write the information
– They fold the billet
– You slide it into your wallet, close the wallet, and you read their mind.
There is no need to go back to your wallet later for the peek.
The workings are very simple, you can use your own wallet (no need to buy a peek-specific wallet), and the materials you will need can be found in your kitchen, or the bakery section of the grocery store.