Mmmmmm FLdigi! I was wondering when I'd start to see people sending e cash into the audio or radio waves. I was thinking about laser modems as well actually which might be fun too. How much data is a single aCash Cashu token? So many lovely modulation schemes to encode the token into. Particularly in unlicenced spectrum. Or maybe sending the audio of a QR code via SSTV to a phone that has an app that demodulates the audio signal into the QR code. Wonderful. Just wonderful.