Show HN: Log in to WordPress via QR code (fully functional plugin available)

Sure. You could have QR code point to a URL on your server that started the oauth login process and had the one time hash value passed as a parameter. That hash value would be put in the callback URL for the oauth process. Once you complete your normal oauth login your server takes the one time hash value and does the same update the db trick done here.

Aside: God, imagine if browser vendors had put a tiny bit of effort into password management or even just the UI around http auth back at the beginning. All sites could use http auth or whatever superceded it instead of their own login forms and this problem would seem just as stupid as it actually is.

I don't use them often but if I'm walking around and someone wants me to open a url on my phone for any reason (billboard, ad, store, restaurant, anything in print) then it better be really short or have the QR code right there for me to even think of bothering.

Still that means I probably use one maybe twice a month, but I would use them more if they were more widespread.

I expect most people are the same, no one types long URLs into their phones while reading them off a newspaper or billboard or store window do they?