If you have been to Japan you must have seen this. You can see it everywhere: on the billboards, postcards, posters, print advertises, flyers, bottles, packages...etc. This is called QR Code. The QR is derived from Quick Response, as the creator intended the code to allow its contents to be decoded at high speed.
The original barcode was invented in America, but the technology was improved in Japan. This QR Barcode was invented in Japan and it's very common in Japan. If you use your Japanese cell phone to scan the code, you can read this code with the camera and access the website without typing the URL manually. Actually, one of the interesting thing I observed is that in Japan, a lot of time, instead of telling you the URL, they either give you this QR Code or tell you how to search it. For example, Japanese Coka-cola advertise, instead of spelling out www.cocacola.co.jp, they would give you the QR code on their priducts or tell you to type in コカコーラ (Coka-cola in Japanese) and search for it. Since I don't have a Japanese cell phone, I can't access the site but search for it.