Latest Marketing Trend to Watch:
QR codes were popularized more than five years ago in Japan and are now used globally as physical world hyperlinks. Like updated versions of traditional bar codes, QR codes are images that can be scanned to relay information. A code scanned by a smartphone instantly links a user to mobile content, fostering greater customer engagement. Big brands are adopting this strategy and you can, too.

Early adopters helped create a 'mystique' surrounding QR-led urban games because they could access exclusive content. (See fun examples here and here.) But now mainstream consumers are seeing more QR codes everywhere. U.S. companies were a bit behind in adoption of these codes until now.

Here are just some of the places people see QR codes in their daily lives:

Also referred to as Mobile Tagging, the strategy of placing these codes in the offline world is gaining popularity in the U.S.  It's a great way to help foster a total customer experience, linking mobile phones to real life. Never before has marketing been able to so effectively bridge everyday activities with content.

A blog commenter sums it up best:
Last year I (temporarily) didn't have a QR code reader in my new phone and it caused problems. (In Japan) we use them for everything from membership card signups, promo emails/discounts and checking food freshness. QR codes are here and it will take something much bigger and better to replace it!!

How To:
QR campaigns in the U.S. are only scratching the surface of the potential use. Here are some ways to get started:

Some bloggers offer suggestions on how to personalize QR codes by adding designs and colors. While some readers allow for up to a 30% margin of error and can still translate the code, it's important to understand that changing the color of a QR code can potentially break it, rendering it useless. Many of us at Gold Lasso tried to scan this Louis Vuitton example and it didn't work. (Note, the landing page is now no longer active, but when the code is scanned, your QR reader should still recognize the link. For most of us it did not. If your smartphone doesn't already have a QR reader, check for some free ones in your service provider's app store.)