Apple iOS 5.0




Apple iOS can be downloaded from iTunes by connecting your iPhone and clicking the Update button.
WHAT'S NEW
Version 5.0:
Notifications

Swipe from the top of any screen to view notifications in one place with Notification Center
New notifications appear briefly at the top of the screen
View notifications from lock screen
Slide the notification app icon to the right on the lock screen to go directly to the app


iMessage
Send and receive more...
REQUIREMENTS
Supports:
iPhone 3GS / 4 / 4S
iPad / iPad 2
iPod Touch 3rd Gen / 4th Gen

Link: