iOS 5.1.1

This update contains improvements and bug fixes, including:

Improves reliability of using HDR option for photos taken using the Lock Screen shortcut
Addresses bugs that could prevent the new iPad from switching between 2G and 3G networks
Fixes bugs that affected AirPlay video playback in some circumstances
Improved reliability for syncing Safari bookmarks and Reading List
Fixes an issue where ‘Unable to purchase’ alert could be displayed after successful purchase

For information on the security content of this update, please visit this website:
http://support.apple.com/kb/HT1222