title
QR Codes - What are they?
QR Codes are two dimensional barcodes that can be decoded using a web-enabled mobile device with a camera.
So What?
The entire world can be hyperlinked!
Images (from left to right) from flickr.com members: clevercupcakes, stan, Fluid Forms, avlxyz, akaalias, manuelbieh (creative commons license) 
How does this relate to libraries and museums?
University of Bath and Kyoto University use QR Codes in their online catalogs
Sacramento Public Library uses a QR Code to load SMS reference contact info into patron's phones
Powerhouse Museum used QR Codes in a recent exhibit
University of Huddersfield Library uses QR Codes throughout the library!



Photos compliments of Andrew Walsh, University of Huddersfield
Photos provided by Sebastian Chan, Powerhouse Museum 
How does it work?
1. Web-Enabled Phone with Camera
2. QR Code App Downloaded to Phone
3. Take a Picture of the QR Code
4. Phone reads it and either
    a. Sends you to a link / Web page.
    b. Gives you a message (text).
    c. Saves a vcard.


Drawbacks
No standards
Have to download an app
Spotty wireless in the library


 
Final Note
Likely to become more popular with Google's Favorite Places:
http://bit.ly/qrgoogle


And...
On books
In books