iOS 5.1 available for download

Improvements and bug fixes:

• Japanese support for Siri (availability may be limited at the initial stage of the service)
• photos can now be deleted from Photostream
• the quick access icon for the camera is now always visible on the locked screen of iPhone 4S, iPhone 4, iPhone 3GS and iPod touch (4th generation)
• the face recognition camera function now highlights all detected faces
• redesigned Camera program for iPad
• Genius Mixes and Genius Playlists for iTunes Match Subscribers
• TV shows and movies on the iPad audio playback optimized for louder and clearer sound
• playback speed controls and 30 second rewind for iPad
• battery time error correction
• correction of the error that periodically led to loss of sound in incoming calls

Supported devices:

• iPhone 3GS, 4, 4S
• iPad 1, 2, The new iPad
• iPod touch 3rd and 4th generation

Direct links:

• iPhone 3GS
• iPhone 4 GSM
• iPhone 4 CDMA
• iPhone 4S
• iPad
• iPad 2
• iPad 2 3G
• iPad 2 CDMA
• iPod touch 3G
• iPod touch 4G

How to install update from ipsw files

• We connect the device to the computer
• Choose it in iTunes
• On Mac OS X, hold down the "option" and click "Refresh"
• On Windows, hold down "SHIFT" and click "Update"
• Choosing an IPSW file