QR Codes
Uses in education - Black and White and Scanned All Over
WWW.QRStuff.com
Lots of free QR readers available in the App store.
QR reading and creating apps:
QR.code - http://www.appolicious.com/tech/apps/2778870-qr-code-greenspace-limited
Red Laser - http://www.appolicious.com/tech/apps/886649-redlaser-barcode-scanner-shopping-assistant-qr-code-reader-ebay-inc
Qrafter - http://www.appolicious.com/finance/apps/554843-qrafter-qr-code-and-barcode-reader-and-generator-ali-kerem-erkan
QR codes are images that can be scanned that immediately link to some online content (web page, image, contact info, podcast, video, text message, etc.)