Rules are simple
1. Find a picture or website
2. Make a QR code http://www.qrexplore.com/generate/
3. Post it on tread

Examples

I believe the Google URL shortening service, http://goo.gl, automatically created a QR code for each URL shortened, and it tracks how many people follow that shortened URL.

This is really hard to utilize on mobile device. In fact, what is the possible use of an on-screen QR code? I only ask because, in the course of my duties as an ad designer, I have occasionally been confronted by people who want to do just that. I'd like a reason that makes sense.

The only reason I can think of putting a QR code on a website is to quickly access it from a mobile device.

Say you're looking up reviews of apps on your computer. That Ninja-Vs-Toaster game looks amazing! I need to download that on my android. But opening up the market and searching puts too much strain on my frail wrists and weary thumbs. I'll just scan this somewhat convenient QR code.

Meh, reasonably useful.

Using Tapatalk, I saved the first QR Code above ro my iPhone's photo-roll, and then opened my QR Code Scanner app and imported it. It worked!

Except that it was much less convenient then just clicking a link.

Keith, what I suspect is that they are using a trackable URL (like the goo.gl one I mentioned above) and end up with a hard-to-type or a hard-to-remember URL, so they QR Code it for mobile users. On the other hand, if I'm already on a computer reading you page, a simple link works just fine! Unless it's for a special mobile only resource like an app or SMS message or something.

Finally, I suspect there is still a "cool" factor that has marketing departments overusing QR Codes for nebulous reasons.

One excellent use of a QR Code, in my opinion, is for business cards. Having one on the back that leads to your website and doesn't require the recipient to gave to enter it is a feature. Also, I don't know how many people realize this, but other content can be encoded, not just URL's. You can initiate a telephone call, or an SMS message, or an email, or just encode a small snippet of text, like a name, password, or home address. They're much more versatile than many realize!

In my work we use these codes to store document information making it easier to index it in a database with the risk of human error.

Yeah I put one on the back the business card I handed out at Gencon last year. I thought it was gimmicky then. We use them at the paper occasionally, to guide people to expanded coverage or in a display ad.

I'm still not convinced they have real longevity. Time will tell, I suppose. In the meantime:

I didn't even know what those were until I saw this thread.