You might have started noticing that when you look through many of today's popular magazines, you'll not only see the usual ads, but you'll also sometimes see a barcode.
These QR (Quick Response) codes are designed to be scanned by YOU! With an App on your device you can use the device's camera to scan the code and usually it will take you to the website embedded in the code so that you can find out more information about the product you're looking at. Perhaps its an article and they have a video on their website that's impossible to show you in print. There are lots of use cases for these codes and it sure beats writing down URLs.
Scan is Fast and Free
One of the first Apps that turned up in my search for a QR Barcode scanner for my iPhone was "Scan". Scan is a free app dedicated to doing one thing. It lets you use the camera on your iOS device (yes including the iPad 2) and quickly scan the code in front of you and fire up the link in the built-in browser. That's pretty much it! It works. You also have the option of sending the page over to Mobile Safari if you want more Safari options than the built-in browser gives you. Scanning of the code is FAST. Usually by the time the camera hits the code I hear a beep and it's firing up the page in the browser. It was so fast in some cases that it was hard to even capture a screen shot of it working.
While the App does exactly what it claims and it's hard to argue with Free, there is one thing I'd like to see added. If I see a code while flipping through a magazine I would think that in most cases I'm interested in the information but may not have the time in that moment to dig deeper. I'd really like to see integration with the "read it later" services like Instapaper and "Read It Later". On the plus side the App DOES have a Scan History. The only problem with it is that it shows the URL which is often a short URL like a bit.ly instead of the name of the site/ad. This could be improved. Otherwise there is no reason not to get this App. It works great!
You can get Scan for FREE here from the 
Generate your own codes here.
This is my default QR Code scanning app. Love it. Clean and simple design. Super fast.