You may have noticed that besides each blog entry’s title there is now a QR code image. QR code is a new type of data representation which supersedes the prevalent 1-D barcode that we find in our everyday life, for example on food labels and some magazines. One of the major advantages of the QR code is that it can store much more information than the 1-D barcode. After given birth by a Japanese company more than 10 years ago, its usage is now very common in Japan. My QR code implementation is for hackish value only. Luckily I find that after a long time I can still code in PHP. It’s fun to see how it works by encoding the title, publishing time and most importantly the entry’s URL in one tiny image, and then see it being decoded by a decoder. If you find that the image is too small, you can right click on the image to view it in full size.