Apple's newly released iPhone 4S, labeled to be a flop phone by many when it came out last week, has already become a huge success among customers, even before it went on sale in stores across the globe Friday, with many of them buying it as a tribute to Steve Jobs.

It is reported that hundreds of fans queued around city blocks in Sydney and Tokyo Friday to be the first to get their hands on iPhone 4S.

The new smartphone from Apple has shattered all preorder records for iPhones and reportedly been completely sold out on Apple's online store, at BestBuy and with service providers AT&T, Sprint and Verizon.

The phone has significant hardware upgrades, though it looks identical to iPhone 4. It is equipped with an A5 chip, iOS 5, Siri Voice assistant and an 8-megapixel camera along with many features.

The arrival of iPhone 4S will trigger a smartphone battle in the U.S. market as its strongest rivals -- the Samsung Galaxy S2 and Motorola Droid Bionic -- have come to this market after several design changes.

Samsung's Galaxy S2 continues its strong march in the smartphone race, giving stiff competition to Apple's iPhone 4.

The Galaxy S2, which runs on the Android 2.3 Gingerbread OS and sports Samsung's TouchWiz UI, comes with an 8-megapixel camera with flash and can record high-definition video in 1080p, offering the richest video content on a smartphone. The phone also has a front-facing 2-megapixel camera for video chat.

The device, which was recently launched in the United States, sold a whopping 10 million units since its launch in late April 2011, not including sales from the U.S., the largest market for smartphones.

On the other hand, Apple sold 20 million iPhones in the third quarter. Though the Galaxy S2's sales lag behind iPhone sales, it implies that Samsung Galaxy S2 is the toughest rival Apple will face for its iPhone 4S.

Meanwhile, Motorola Droid Bionic has undergone several design changes. At the beginning of this year, this smartphone looked like the Motorola Atrix, but now it looks very similar to Motorola Droid 3, one of the latest high-end phones. However, Motorola Droid 3 has a slider QWERTY, unlike Droid Bionic, which is just a touchscreen phone.

Other changes in Droid Bionic include higher RAM capacity, a change in chipset from the Tegra 2 AP20H to the TI OMAP4430 and, surprisingly, less battery capacity compared with the battery capacity introduced in previous iterations of the phone.

Meanwhile, the new smartphone from Apple received positive reactions from technology gadget reviewers for its new voice-recognition software, faster processing speed and improved picture-taking quality, Bloomberg reported.

Perhaps, the most prominent feature is Siri - a voice-recognition feature that allows users to control their phones by talking to them. The feature will allow users to control their iPhone using just their voices. iPhone 4 already has a Voice Control system but it is very limited. The new system is supposed to recognize more natural phrases and have a much greater tolerance for nebulous inputs.

Phil Schiller, Apple's marketing executive, called Siri the coolest feature of the new iPhone 4S.

To access Siri, users will have to hold down the home button for a few seconds and the application will launch. It works quite well, and it can do a lot of things, even more than Google's Voice Control can.

Siri helps you make calls, send text messages or email, schedule meetings and reminders, make notes, search the Internet, find local businesses and get directions. Users can also get answers, find facts and even perform complex calculations just by asking.

David Pogue, the New York Times reviewer, says Siri is crazy good, transformative, category-redefining speech recognition, Bloomberg reported.

The other big thing that is overhyped by Apple is the camera. The device has an eight-megapixel camera with improved optics and the larger f/2.4 aperture work together to let you take better pictures. The camera also uses advanced algorithms in iOS 5 for even more color accuracy, better white balance and greater dynamic range. It also supports 1080p HD video recording with real-time noise reduction and video stabilization.

Coming to the processer, iPhone 4S is Apple's first A5 dual core processor smartphone, the same one used in iPad 2, which also has a new and improved graphics adapter that should provide up to 7 times the performance in games and other intensive graphics apps compared to the A4.

So the heated battle will begin with the arrival of the Apple iPhone 4S. All the three smartphones are right up there in the hype cloud, and hopefully they will live up to it.

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