If you need a past or present iPhone, iPad, iPod touch, or Apple TV iOS 5 firmware file, we've got 'em all here. Just browse to the device you want and click the firmware file you need. Your download should automatically start. All downloads are the official Apple firmware release versions.
iPhone 4S
iPhone 4 (GSM)
iPhone 4 (CDMA)
iPhone 3GS
New iPad (3rd gen) - Wifi only
New iPad (3rd gen) - GSM
New iPad (3rd gen) - CDMA
iPad 2 - GSM
iPad 2 - CDMA
iPad
iPod touch (4G)
iPod touch (3G)
Apple TV 3
Apple TV 2
Source: Apple.com