Updating my iPhone to iOS 6 has been an interesting experience. The new maps app built in-house by Apple is rather underwhelming when compared to the Google Maps it replaced. Conversely I found the Passbook app to be promising. The app essentially pairs with other apps on the phone to create full screen "cards" for boarding passes, movie passes etc. There relatively few apps that work with passbook at the moment, but I am sure the number will increase as developers have time to add functionality to their apps.
As I worked with the app, I imagined a library using passbook the give users a "virtual library card". The library could brand the card just like a regular card, and could also include information about checked out items, nearest branch hours, or branch address information. When the user enters the library the card would appear in the lock screen and the user could quickly access it at the circulation desk. As smart phones becomes more imbedded in users lives the library could develop tools like passbook to connect to mobile users beyond a mobile OPAC.