Also, QR codes were invented by the Japanese to track car vehicle parts way back in 1994, so it's no wonder they're ubiquitous there already. Here in the States, however, they're just beginning to catch on a little bit. QR stands for quick response—as in, you scan the code with your phone's camera and you're immediately taken to whatever the code has be programmed to do. The code might send you an SMS, it might take you to a Web page, it might trigger a video or even have your phone call a phone number.
Recently, we got a Target catalog in the mail with a bunch of QR codes next to some of the toys. When you scan one, you get a video commercial showing you what the toy could do. Likewise, New York Times tech writer Nick Bilton's new book, I Live in the Future & Here's How It Works. uses QR codes in conjunction with video. Each chapter has a QR code at the top of it and when you scan them, some take you to YouTube videos of Nick talking about the chapter. You get to meet the author through the video and even interact with him through the YouTube vid comments.
Many Nokia phones are now coming with scanners and code readers built into them. Then there are all the wonderful free apps available for download to iPhones and Androids and the like. My favorites include ScanLife, RedLaser and Mobiletag. If you get a little high off of scanning groceries at those automated check-out lanes, you'll really love using QR codes. For more, check out the Rocketboom video below.