QR Codes: bridging analog and digital data
My QR Code
We are all familiar with bar codes. Some black strips are printed on paper. A scanner reads it and converts it to digital data (in most cases grocery prices). Pretty neat stuff. We had an electronic organ back in the early 80’s that did the same thing, but in place of prices, it converted sheet music to digital sound.
QR codes are essentially the same thing. But instead of having a dedicated reader in the case of bar codes, all you need is a cellphone camera with a QR code reader software in it. Take a picture of a printed or on-screen QR code and the software will translate that into some simple text, like a url or your very own personal sig.
Here is a QR code reader software for your mobile phone.
Google for more. There are lots online.
My interest in QR codes tickled the crypto-junkie in me. It’s a nice way to pass encrypted GPG ascii-armored text via pictures only. You can make actual paper backups of your keys. But I don’t think QR codes support all that much text. If you know of something similar that can support a thousand lines of text please tell me about it 
