The use I see for it is in providing access to critical information in the event of injury or death. One key to family, one to friends, one in a safety deposit box, etc. Copies of legal records and sensitive info can be given to people without the risk it would be misused.<p>The other use is handing/hiding them out at a convention and making a big ARG out of it. Which sounds like a lot more fun
Another use case: use it to bring people who are estranged together. Put some crypto wallet seed in it. And give it to them and tell them they have work together to access the money.