If you’ve consumed any media at all recently, you may have noticed strange looking squares on signs, magazines, billboards, webpages, and even buildings. These squares are QR codes. QR (Quick Response) codes are a type of barcode, similar to the barcodes you see on everyday products in grocery stores. These QR codes often contain URLs that direct users to sites where they can learn more about a place, product, or particular subject.

One of the reasons that QR codes have increased in popularity is the near-ubiquity of camera phones. If you have a smartphone, you have a QR code reader. When encountering a QR code, all you have to do is snap a picture with a QR code-compatible application, and you will be taken to a site with more information about the item to which the QR code is attached. Sometimes, QR codes can even direct you to a physical location—say you’re on a walking tour or in a museum, for example, that has QR codes on its floorplan. Take a snapshot, and directions are immediately imported into your phone.

QR codes may look like complicated gibberish, but they’re pretty simple to create. There are several web sites that will create a QR code for you in just a few clicks. For example, I created the QR code above by going to the ZXing Project web site, selecting URL from the dropdown, entering a URL, and clicking on Generate.

Now, anyone with a smartphone and a QR-capable application, like the Google app (check availability for your phone on the Google Mobile App site), can snap a picture of that QR code, and be taken to the embedded URL, in this case, lynda.com.

QR codes are often used by businesses as extensions of marketing campaigns, to deliver promo codes, or to take users to a web site. However, given how easy they are to create, they’re also becoming more popular for personal use, like party invites and relaying contact information. Meanwhile, companies like the BBC are not only using QR codes to promote their programs, but have also started customizing their QR codes with their own logos. Because of the amount of data that QR codes can contain, they’ll function properly even if a significant chunk is obscured, depending on the size and placement of the logo:

In both cases, despite the presence of the logos, there’s enough of the QR code for a QR reader to read. The danger of adding images or logos, however, is that camera apps like Google’s will often recognize the image, and output info on the image itself, rather than take the user to the desired URL embedded in the QR code. Therefore, the images in the QR codes above were altered in ways to fool the Google app into reading only the data in the QR code.

While the QR codes above do a nice job on incorporating logos and images into the barcodes, this one made for Louis Vuitton and artist Takashi Murakami blows other QR codes away. It’s more like a piece of art that happens to have a QR code in it. If you’ve seen others great QR codes, or made some custom QR codes yourself, feel free to leave them in the comments section for all to see.

To read more on QR codes, and tips on how to use and create them, check out these pages:

13 Creative Ways to Use QR Codes for Marketing – Fast Company
7 things you should know about QR Codes – Educause