It would be interesting if an opendime-like or hardware-wallet device could facilitate bitcoin transfers offline. This could potentially work by locking coins and swapping transactions directly via the hardware wallets, kind of like the lightning network uses off-chain pre-signed transactions.

This would necessarily require some trust in the user and/or device used. Obviously, a tampered-with device could simply double spend a number of coins. However, if the users involve trust that the hardware device is not compromised (perhaps because the company making it has a good reputation for making them secure), it should be possible to make offline transactions. If the company (or a government) goes further to deter people from double spending (either via tampered-with devices, or counterfeits), it could bolster trust in it further.

But basically, you could timelock coins into a wallet where they aren't spendable until a later date, and when you want to pay someone, you give them a transaction that gives them future ownership over those coins. The additional counterparty risk might be acceptable for small amounts when internet isn't always available. Whenever internet becomes available, the commitments could theoretically be cemented at that point to prevent any possible future double spends.

Mostly interesting musings ^