Yesterday i finally upgraded my iPhone 3GS to iOS 5 and below are the changes / updates / upgrades is what i saw. I thought it would be good option for anyone to go through the features below before upgrading :)

The products that are compatible with this upgrade are:

- iPhone 4S

- iPhone 4

- iPhone 3GS

- iPad 2

- iPad

- iPod touch (4th generation)

- iPod touch (3rd generation)

This update will give more than 200 new  features. Most of them are listed below:

[highlight]Notifications[/highlight]

- Notification center gives you the flexibility to see all the notifications in one place. All you have to do is swipe from top of any screen to bottom.

- New notifications will appear briefly at the top of the screen.

- You can view notifications from lock screen as well.

- Also sliding the notification app icon to the right on the lock screen will take you directly to the app.

[highlight]iMessage[/highlight]

- After this upgrade you can send and receive unlimited text, photo and video messages with other iOS 5 users.

- Message tracking with delivery receipts and read receipts

- Group messages

- Secure encryption

- iMessage will work with both cellular network and Wi-Fi

[highlight]Newsstand[/highlight]

- Newsstand automatically organizes magazine and newspaper subscriptions on Home Screen

- Newsstand displays the cover of the latest issue

- Newsstand downloads new issues in background.

[highlight]Reminders[/highlight]

- iOS 5 has reminders for managing to do lists

- Reminders syncs with iCloud, iCal and Outlook

- Only for iPhone 4 and iPhone 4S reminders has location based reminders when you arrive or leave a location

[highlight]Twitter Built in Support[/highlight]

- Once you sign in from settings, you can tweet directly from Camera, Photos, Maps, Safari and YouTube

- You can add location to your tweets.

- You can also view twitter profile pictures and username in contacts.

[highlight]Camera Improvements[/highlight]

- Volume up button can be used for taking the picture.

- There is an option of gridlines to line up shots

- Pinch to zoom in the preview screen

- You can swipe to camera roll from preview screen.

- You can double click on the home button when device is asleep to bring up a camera shortcut on iPhone 4S, iPhone 4, iPhone 3GS and iPod touch (4th generation)

- Tap and hold to lock focus and exposure, iPad 2 and iPod touch (4th generation) only support exposure lock

[highlight]Photo Improvements[/highlight]

- You can crop and rotate photo.

- Red eye removal.

- One tap enhance.

- You can organize photo into albums

[highlight]Mail Improvements[/highlight]

- You can format text using bold, italic and underline fonts

- Now you have indentation control.

- You can just drag to rearrange names in address fields.

- You can flag messages.

- You can mass mark messages as flagged, read or unread.

- You can customize mail alert sounds

- S/MIME support

[highlight]CalendarImprovements[/highlight]

- Year view for iPad and new week view for iPhone and iPod touch.

- You can tap to create an event.

- You can view and add event attachments.

[highlight]Game Center Improvements[/highlight]

- You can now use personal photos for you game center accounts

- You can compare your overall achievements score with your friends

- Find new Game Center friends with friend recommendations and friends of friends.

- You can discover new games with custom game recommendations.

[highlight]AirPlay Mirroring for iPad 2 and iPhone 4GS[/highlight]

[highlight]Multitasking gestures for iPad[/highlight]

- You use four or five fingers to pinch to home screen.

- You can swipe to reveal the multitasking bar

- You can swipe left or right to switch between applications

[highlight]Device setup, activation and configuration with Setup Assistant[/highlight]

[highlight]Software updates available over the  air without tethering[/highlight]

[highlight]iCloud Support[/highlight]

- iTunes in the Cloud

- Photo Stream

- Documents in the Cloud

- Apps and Books automatic download and purchase history

- Backup

- Contacts, Calendar and Mail

- Find My iPhone

[highlight]Redesigned Music App for iPad[/highlight]

[highlight]Hourly Weather Forecast[/highlight]

[highlight]Real-Time Stock Quotes[/highlight]

[highlight]Wireless sync to iTunes[/highlight]

[highlight]Keyboard improvements[/highlight]

- Split keyboard for iPad

- Keyboard now has improved auto-correction accuracy

- Keyboard is improved for Chinese and Japanese input

- New Emoji keyboard introduced

- Personal directory for auto-correction

- You can now optionally create keyboard shortcuts for frequently used words.

[highlight]Accessibility improvements[/highlight]

- Option to light LED flash on incoming calls and alerts  for iPhone 4S and iPhone 4

- Custom vibration Patterns for incoming calls on iPhone

- New interface for using iOS with mobility-impairment input devices

- Option to spask a selection of text

- Custom element labeling for VoiceOver.

[highlight]Exchange ActiveSync improvenments[/highlight]

- You can now Wirelessly sync tasks.

- iOS now has improved offline support

- You can also save new contact from a GAL Service.

[highlight]More than 1,500 new developer APIs[/highlight]

[highlight]And of course bug fixes[/highlight]

[highlight]For more information visit[/highlight]

http://support.apple.com/kb/HT1222