We already said that Apple Inc. has been released iOS 4.2, and did you know that, new iOS 4.2.1 8C148 is not small size, it’s almost 0.5 GB on each devices. For iPhone 4 example, the update iOS 4.2.1 8C148 IPSW almost 650MB. That’s bad option for slowly internet connection like me. So I tried to googling and found the solution about it.

iOS 4.2.1 for iOS Device Family

After searching somewhere, the best option is Download iOS 4.2.1 8C148 IPSW and restore to your iPhone/iPad/iPod Touch using Manual Method. Before we update manually, please download iOS 4.2.1 for you device

• iPhone 3G
• iPhone 3GS
• iPhone 4
• iPod Touch 2G
• iPod Touch 3G
• iPod Touch 4G
• iPad

After you successfully download, follow this guide to update your iPhone/iPad/iPod Touch into iOS 4.2.1 8C148. Please notes, you need to update your iTunes into 10.1 before starting updated into iOS 4.2 then follow this guide

1. Connect your iPhone/iPad/iPod Touch to the computer.
2. Choose your device from the left sidebar.
3. Press the Shift key(in Windows) or the option key(in Mac OS X), click on the Restore button.
   Or You can update by click update button but in the same time press Shift Key (windows) or Option Key (Mac OS X)
4. Now browse to the iOS 4.2.1 8C148 IPSW file and select it.

Congratulations, now you have iOS 4.2.1 Installed on your iOS Devices

Starting November 22, 2010, Apple has been released iOS 4.2 for many Apple iOS Devices, there are iOS 4.2 for iPhone, iPad, iPod Touch and now available for download.

AirPrint on iOS 4.2 Update

There are many features introducing in iOS 4.2 such as

• Multitasking on iPad
  iOS 4.2 brings multitasking from iPhone and iPod touch to iPad. So you can be more productive as you work, have more fun as you play, or do a little of both. Everything happens smoothly and efficiently — without slowing down the performance of the foreground app or draining the battery unnecessarily.2
• Folders on iPad
  Now your iPad has more room for more apps. Move apps into folders with drag-and-drop simplicity to declutter your Home screens and keep your apps organized for fast access to your favorites
• AirPlay
  AirPlay lets you stream digital media wirelessly from your iPhone, iPad, and iPod touch to your Apple TV and AirPlay-enabled speakers. So you can watch movies and photos on your widescreen TV and play music through the best speakers in the house.
• AirPrint
  AirPrint makes it simple to print email, photos, web pages, and documents right from your iPhone, iPad, or iPod touch. A few taps is all it takes to go from viewing it onscreen to holding a printed copy. There's no software to download, no drivers to install, and no cables to connect.
• Find My iPhone, iPad, or iPod touch.
  Find My iPhone, iPad, or iPod touch — the MobileMe feature that helps you locate your missing device and protect its data — is now free on any iPhone 4, iPad, or fourth-generation iPod touch running iOS 4.2.3 Once you set it up, you can find your lost device on a map, display a message on its screen, remotely set a passcode lock, and initiate a remote wipe to delete your data. And if you eventually find your iPhone, iPad, or iPod touch, you can restore everything from your last backup.
• Messaging with text tones
  Know who's texting without looking at your screen. Choose from 17 new alerts and assign custom tones for people in your contact list.
• Keyboard and dictionary enhancements
  iOS 4.2 includes support for over 50 languages and dialects, with more than 30 new international keyboards and dictionaries for iPad.

And many more. On our iPhone 4, the update not yet avaliable, So I try to find tutorial How To Manual Update iOS 4.2, You can Read more details, Tutorial How To Manually update on iOS 4.2.1