iPhone 4S, Apple's long-awaited new gadget, will be on sale in stores across the globe at 8:00 AM (local time) on Friday. The excited fans are already lining up outside the stores, trying to be the first to get their hand on iPhone 4S.

iPhone 4S, which looks similar to iPhone 4, has a better processor that guarantees to deliver up to two times more power and up to seven times faster graphics.

The latest iPhone also has a better and faster camera, dual-core graphics, and a new alternating antenna system for better sound quality and reception.

The Siri, a state-of-the-art personal assistant, makes iPhone 4S smarter and helps the user create and send texts and e-mails, set up meetings and reminders, get directions, call friends, and play music.

Moreover, iPhone 4S, which is the last iPhone unveiled during Steve Jobs' lifetime, has a special meaning for the fans who want to buy the smartphone as a tribute to the legendary tech genius.

The suggested retail price of iPhone 4S is $199 (US) for the 16GB model, $299 (US) for the 32GB model and $399 (US) for the new 64GB model on a standard two-year contract.

However, if people don't prefer two-year contracts, they can purchase unlocked versions of iPhone 4S, which are priced at $649 for the 16 GB model, $749 for the 32 GB model and $849 for the 64 GB model. The unlocked iPhone 4S works only on supported GSM networks. If the users are outside the U.S., they should replace with a micro-SIM card from a local GSM carrier.

iPhone 4S is also available in two colors - black and white. People can purchase from Apple Online Store, Apple's physical stores, wireless carriers or networks such as AT&T, Verizon and Sprint, and select authorized resellers, which include Best Buy Co. Inc. and Wal-Mart Stores Inc.

By the end of Oct., iPhone 4S will be on sale in 22 more countries, such as Austria, Belgium, Czech Republic, Denmark, Estonia, Finland, Hungary, Ireland, Italy, Latvia, Liechtenstein, Lithuania, Luxembourg, Mexico, Netherlands, Norway, Singapore, Slovakia, Slovenia, Spain, Sweden and Switzerland.

Here's a review the top 8 new features of the latest iPhone. Get ready to stand in the line if you want to get your hands on Apple's latest smartphone.

1. Siri: Siri is one of the most-anticipated features of iPhone 4S. When the users talk with the Siri, it will help you to send messages, schedule meetings, place phone calls, and more. The smart software can know what the users are saying and, if necessary, it can even respond to the demand.

What we really want to do is talk to our device. Siri is your intelligent assistant and helps you get things done, just by asking, says Phil Schiller, Apple's marketing chief.

2. iOS 5: iOS 5, the most advanced mobile operating system by Apple, includes more than 200 new features and can be installed on the iPad, iPhone, or iPod Touch. It boasts of features such as Notification Center, iMessage, Newsstand , Sarfari, Reminders, Twitter etc. If people have mobile Apple device, they can download iOS 5 for free.

3. Camera: The upgraded camera can now shoot 8-megapixels stills (3264 by 2448 pixels) and record 1080p HD videos at thirty frames per second. The camera offers better clarity, better white balance, and color accuracy. Furthermore, iPhone 4S has all-new optics.

4. iCloud: iCloud, which can store all your stuff including music, photos, apps, mail, contacts, calendars, documents, and more, provides the easiest way to help the users manage their content.

 iCloud is the easiest way to manage your content, because iCloud does it all for you and goes far beyond anything available today, said Eddy Cue, Apple's senior vice president of Internet Software and Services. You don't have to think about syncing your devices, because it happens automatically, and it is free.

5. Dual-core A5 Chip: Dual-core A5 chip, which makes iPhone 4S be quick and responsive, deliver up to two times more power and up to seven times faster graphics.

It will make all the difference when you’re launching apps, browsing the web, gaming, and doing just about everything, for the A5 chip is so power-efficient.

6. Retina Display: Retina display is the highest-resolution screen available on a smartphone ever. Because the pixel density is so high, the naked eyes can't even distinguish individual pixels. The display is more remarkable than the printed page and the users will notice crisp text, sharp graphics and stunning images.

7. 1080p HD Video: 1080p HD Video can help users shoot stunning videos wherever they go. Because it comes with all-new optics, the light is always right and the color is always vivid. More importantly, the user can also edit the video on the iPhone 4S.

8. FaceTime: FaceTime can let the users to hear a voice and see the face . No matter where the users go, they can see their family or friends face to face. Using the FaceTime is like making a phone call, albeit a video call.