Some smartphones come with a barcode reader already installed as part of the standard software. All smartphone providers (including Mac, Android, Nokia, Blackberry) have an app store or marketplace that allows you to download applications - you will usually be able to open this direclty from your phone.
Search for 'QR code' or 'QR reader' to find an application that suits you, or try these links for a list of suitable readershttp://www.mobile-barcodes.com/qr-code-software
You may also see QR codes at the ends of the Library shelves to give you quick access to Library guides relevant to that subject area.
Tell us what you want - Is there a service in the Library that you would like to access via QR code? Let us know your thoughts!