I read about QR codes a couple of weeks back thanks to a comment on Twitter. I wasn't particularly interested the first time around. I had some extra time this week at our Tech Camp, so I explored it a little more. Here's a link to a livebinder that will give all the explanation you need about QR codes. It also has examples of how to use it in class. I found most of the applications to be not that helpful. I'm going to share two applications that I see using QR codes for. First, I like the idea of having a paperless answer key to go with a worksheet. A QR code can be placed on the worksheet. When a group of students have finished their work, they can check their answers can be scanning the QR code with their phones. Now, they will have access to a paperless answer key. Here's a very simple example of a QR code that I linked to a GoogleDoc. If you scan this image with an app on your smart phone, it will send you to an answer key.