This week's book giveaway is in the Mac OS forum. We're giving away four copies of a choice of "Take Control of Upgrading to Yosemite" or "Take Control of Automating Your Mac" and have Joe Kissell on-line! See this thread for details.
QR code can be said an extension for barcode. While the barcode use much more space for less number of character and does not support UTF chars like kanji or kana, the QR code support kanji,kana and takes much less space.