The ubiquitous QR ("quick response") codes that appear on everything from parking pay stations to soda cans and promotional ...

You’ve almost certainly used QR codes before—it’s when you point your phone’s camera at a square barcode to access a menu, a form, or even an app, and then tap on the link that appears.

There’s a catch, of course. It’s a QR clock — the fortune is encoded in a QR code instead of being displayed in human-readable form. You have to take a picture of the tiny OLED screen to ...

At this point, you’re likely aware that you can store your wireless network’s credentials in a QR code, so that anyone who wants to connect with their smartphone need only scan the 2D barcode.