Apple just released an update for the iPod Touch, iPhone and iPad.

iOS 5.1.1 is available for download.

Release notes from Apple:

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

5.1.1 can be downloaded directly in iTunes or over-the-air on an iOS device running 5.0 and higher. Jailbreakers should stay away from the update for now. Everyone else is free to update.