[Cryptography] distributing fingerprints etc. via QR codes etc.

[John Kelsey]

Making it easy to go from "I am standing with this person I know" to "We have exchanged public keys" seems pretty useful in many situations, and that's something it looks like you can do with QR codes.  

A useful hack, IMO, would be something that let me take someone's picture and a picture of their PK (via a QR code), so that email from them would bring up the right picture.

--John