iOS 4.0 is the latest version of firmware for iPhone. It brings some fantansy features:

• FaceTime.
  Finanlly, you can video call your friends with iPhone. With just a tap, You can share your smile to the whole world via Wi-FI with FaceTime.
   
• Multitasking.
  With the revolution iOS 4 multitasking, You can run your favorite apps in background and switch between them in seconds.
   
• HD Video Recording.
  iOS 4 support 720 video recording now.
• Folders for Apps.
  It’s a new way to organize your apps. You can create a folder an move many related apps into it. Is it your iPhone more clear now?
  

Where to manual download iOS 4?

Here are url list to download it:

iOS 4 for iPhone 4:
http://appldnld.apple.com/iPhone4/061-7380.20100621,Vfgb5/iPhone3,1_4.0_8A293_Restore.ipsw

iOS 4 for iPhone 3GS:
http://appldnld.apple.com/iPhone4/061-7437.20100621.5urG8/iPhone2,1_4.0_8A293_Restore.ipsw

iOS 4 for iPhone 3G:
http://appldnld.apple.com/iPhone4/061-7436.20100621.58Yt4/iPhone1,2_4.0_8A293_Restore.ipsw

iOS 4 for iPod Touch 3rd Generation:
http://appldnld.apple.com/iPhone4/061-7381.20100621.AzSP9/iPod3,1_4.0_8A293_Restore.ipsw

iOS 4 for iPod Touch 2nd Generation:
http://appldnld.apple.com/iPhone4/061-7435.20100621.tr49t/iPod2,1_4.0_8A293_Restore.ipsw

Now, You can enjoy your iPhone or iPod touch with latest revolution features from Apple!

Manuals for iPhone 4:

	iPhone User Guide (Manual for iOS 4 Software)
	iPhone 4 Finger Tips – Quick Start Guide
	iPhone 4 – Important Product Information and Safety Guide

Manuals for iPhone 3GS:

	iPhone 3GS User Guide(Manual)
	iPhone 3GS Quick Start Guide – Finger Tips
	iPhone 3GS – Important Product Info and Safety Guide

Manuals for iPhone 3G:

	iPhone 3G User Guide(Manual)
	iPhone 3G Quick Start Guide – Finger Tips
	iPhone 3G – Important Product Info and Safety Guide

You can get more iPhone manuals from official website: http://www.apple.com/support/manuals/iphone.

All manuals are created as PDF format. You may download Adobe PDF reader from here: http://get.adobe.com/reader/.