The lone wolf librarian muses on the topic here, and this is a prezi on the topic.
The quickest way I can think to test it would be to pick a website you want to promote for a topic, go to a QR code generator - they seem to be everywhere - like this one http://goqr.me/ and follow the simple, simple, simple instructions to generate your qr code. You can download the image, and print it off to display in the library or embed it like this on a blog or website.
And if you have a smart phone, and have downloaded the app (and that takes about 5 seconds) you, or your students/patrons can scan the QR code and get the link to some divinely inspired music. If you can't be bothered with all that, you might also toddle off to TED Talks and watch the video clip here. Not half as much fun, though.
BTW 15 minutes prior to writing this blog post, I knew absolutely nothing about QR codes. Now I have found out what they are, how to generate them, how I can use them, and why I want to keep thinking about it.
