They are everywhere! Even the new business cards of my company has a QR-Code on the back now. The most prominent application for them must be in advertisement, where the little block of visual bits forms the connection between print media and online content. The idea is simple: For example, on some poster that already got your attention they put this square of black and white spots. With a camera and an app on your mobile (for example Barcode Scanner on Android) you take a picture and *bam* your phone has just decrypted the URL within the code, which you can then visit without typing a single letter. Basically it works like a Barcode but with two dimensions. The one on my business card contains all my contact information, so you don’t have to scan it or even type it into your phone.

Now this dude, found out that according to the specification, a lot of the code (up to 30%) can be “unreadable” by the phone and still be decoded. So he did the obvious, he put some stuff inside the code like so:

You should try it yourself, it actually still works and in this example gives you the URL of Mozilla Firefox if you scan it. This is actually a pretty sweet idea and if I would make my own business cards with a QR-Code on them, i would definitely integrate a logo like this as well.

Read the full Article with all the explanation why and how it works on

Check out The Top 10 QR-Code Generators in case you would like to try creating your own Codes. In addition, here is a small clip of another interesting application of QR-Codes in Korea where you can go shopping in a virtual store.