I have ideas in the middle of the night sometimes, which usually disappear into the aether because I’m not in a position to act on them. Last night’s particularly choice morsel, which I had Irma email me (I got that ‘look’ and she said I should write it down) is this:
In some east asian countries a person has a chop or seal. It’s kind of like your signature in the west. It’s a quasi-official stamp. You’d have an artist carve you one, and it would be a near-literal representation of you. Where your chop stamped, you said it. So now we have qr codes, 2 dimensional bar codes which can contain from 25 to 2500 alphanumeric characters. They’re probably kind of hard to carve, and lend themselves well to 3d printing. I’ve been thinking for a while about ways to slap uniqueish imprints on things, and it seems like an inked or reflective waxed 3d qr code chop would be a cool way to do it. You could add some text around the edge, but you’d be able to read the data in a cell phone app. The 77 or 114 alpha character limitation means you can’t embed, say, your public crypto key, but you could put a name/email/url/signed bit combo in there, or something like that.