A QR Code is on the cover of the October edition of Deliver, the United States Postal Service’s bi-monthly magazine for marketers (image below). The instructions read: “Puzzled by our cover image? Here’s what you need to do: 1. Download a barcode reader for your mobile phone. 2. Now open it and use your phone’s camera to read the QR code on our cover. 3. Be amazed at what you see”. The code scans as http://www.delivermagazine.com/ but for users with mobile devices, user agent detection (and browser detection) takes them to the mobile site.