Here's a much more fun example of a QR code prank: http://fbcdn-sphotos-a.akamaihd.net/hphotos-ak-ash4/302963_1... (totally SFW of course)
The trivial technical solution is a QR code reader which tells you where you're going before it sends you there, which ZXing (the Barcode Reader for Android) and several iOS QR readers already do.
But anyhow, most URL shorteners offer an API to retrieve the long URL. You could implement that in your QR code scanner as well, for the most popular URL shorteners, to allow people to see where they will be redirected to.
Or perhaps what would be even more fun, is I could put download links for movies on their own posters.
I insist that I check all QR codes before they're sent out, and I scan them with 2-3 different QR scanning apps.
As another commentor mentioned, I often send our QR codes to a redirector URL - either a branded redirector service I built, or to a WordPress site with the redirection plugin, or even to it's very own domain name which is configured for forwarding.
Some of their MPU adverts had QR codes in them, and I called this out on Twitter telling them it was moronic to think that anyone would want to scan the QR code off an advert rather than just click it. Their response was that in their testing of many different adverts, the ones with QR codes were getting the best CTRs. They didn't know the reason for this, and neither do I - but it's interesting none-the-less.
I'd imagine that quirkiness of a QR code to the average user would pop-out of the page quicker and catch their attention faster than a normal image would.
(They were also tracking QR scans seperately, but didn't say how well that was going.)
So for example point the link to http://mysite.com/qr
where you have a little redirection-php file that you can edit at all time.
For the record, I agree with reviewing the URL before hitting it, but if the domain matches what I expect, I'd be strongly inclined to trust the rest.
Mix a QR with a little punycode and you easily can end up anywhere, even if you do (quickly) review the URL before the jump.
He sounds like he wouldn't do it on principle, but I don't understand the technical reason why he couldn't.
And even if he was willing to have his blog redirect to that other site, there's still the issue about all these other misprinted codes. If they point to $randomblog it's mostly funny. If they point (via the redirect) to $possible_competitor, it's much worse
There is no technical barrier to redirection. What he actually says is "What does that mean? I’m guessing they think I can somehow magically cause that QR Code (which they accidentally used in something printed?) to redirect to another URL. I don’t think they understand that the QR Code IS the URL."
Notice the word order. He's "guessing what they think", and his guess is that they think he can "magically cause the QR code to redirect to another URL" -- the object of the sentence is not his domain, and not his URL, but the QR code. (He's saying that they've phrased it as if there is a QR code database where the code must be looked up.)