QR stands for Quick Response Code.
They are barcodes that link to text, a video, a website, launch a tweet, and more.
Yes, they have been popping up on posters, menus, etc... all around town.
You need a smart phone with a QR code reader. (or an iTouch/iPad etc...)
OF COURSE! Very. About half of all cell phone users already have smart phones and in just a short period of time almost everyone will. Take advantage of this emerging technology and include them in your classroom now!