In the 21st century we are going to use QUICK RESPONSE codes: QR codes.
In Korea you can buy food at the train station by scanning the QR code on the packet.
Many important companies use QR codes to send a lot of information to the clients:
Coca cola, Ford, Calvin Klein, Gap, Starbucks and the television channel HBO.
Smart phone users scan the QR code on the item with an application and go to the website or blog or social network.
At conferences QR codes can be printed on T-shirts...
Here is a video about QR codes:
Here is the QR code for this blog: