For the past months, I’ve been working on a functional prototype that allows sending BTC without an internet connection, using SMS and a Raspberry Pi. This solution could help in remote areas, blackouts, or censorship scenarios where data access is unavailable.
If the internet is down then cell phone towers are most likely down as well, and can be censored too.
When I read your title, I first imagined a bluetooth solution much like the recent announcement of Bitchat
1, or something like
Bitmessage. It would not work for realish time payments, but it would allow anyone to send bitcoin to anyone else with no centralized communication infrastructure.
1Currently in beta, available via iOS TestFlight (limited to about 10,000 users) and Android; full App Store release pending optimizations and approval