Apple iPhone 3GS

Design
iPhone 3GS looks exactly like the previous model. It shares the shape and the same external controls, but the iPhone 3GS is unique in a handful of ways. You can get both memory sizes in white or black, and the iPhone 3GS display sports a fingerprint-resistant oleophobic coating that is supposed to attract fewer fingerprints and smudges. The new model shares the same dimensions as its predecessor, but it's slightly heavier, 135 grams. Its dimension is 115.5 x 62.1 x 12.3 mm. It is available with 8 GB, 16 GB, or 32 GB. At 3.5 inches and 480x320 pixels at 163 dots per inch and still produces brilliant colors, sharp graphics, and fluid movements. The layout of the home screen is identical to that on the first version, though it brings two new icons from the outset: A Contacts and the App Store icon to open the iTunes App Store. The display's glass surface, accelerometer feature, touch interface, and secondary menus remain the same.
The iPhone's 3GS controls reveal a few changes, but none will surprise a current iPhone user. The Home button sits below the display, while the volume rocker and ringer mute switch rest on the left spine. The Power/sleep button rests on top of the phone in its normal position. All controls are now silver instead of black. The SIM card slot has not moved either, and Apple now includes a SIM removal tool in the box. At the bottom, there are the speaker, the microphone, and the charger port. iPhone 3GS uses 3.5mm standard headset jack so we can use any 3.5mm headset.

Operating System
iPhone 3GS uses iOS 3.0 from Apple when it was first released, but you can update to iOS 4.3.3. The OS 3.0 is a significant update that promises 100 new features, including such long-awaited gems as multimedia messaging, stereo Bluetooth, a voice recorder, and cut, copy, and paste. It powered by 833 MHz (underclocked to 600 MHz) ARM Cortex-A8 Samsung S5PC100 processor and PowerVR SGX535 GPU.
The home screen can be accessed at any time by a hardware button below the screen, closing the open application in the process. By default, the Home screen contains the following icons: Messages (SMS and MMS messaging), Calendar, Photos, Camera, YouTube, Stocks, Maps (Google Maps), Weather, Voice Memos, Notes, Clock, Calculator, Settings, iTunes (store), App Store, and Digital Compass (new one in iPhone 3GS). Docked at the base of the screen, four icons for Phone, Mail, Safari (browser), and iPod (multimedia player) delineate the iPhone's main purposes.
It supports to run multitasking application. Now, you can run your favorite third-party apps — and switch between them instantly — without slowing down the performance of the foreground app or draining the battery unnecessarily. Or you can listen to a ball game while emailing. Or receive a VoIP call while playing a game.

Multimedia
iPhone 3GS uses a 3.0 megapixel camera with autofocus, touch focus, and geo-tagging. Apple did not include options such as white balance, a digital zoom, or a self-timer. It supports to record video in VGA quality at 30 fps. Apple offers an easy-to-use video-editing option right on the phone.
 The quality to play music is always as good as other Apple’s product. Music and video quality were largely unchanged. It continues to deliver an excellent music and video experience.

Internet and Connectivity
iPhone 3GS uses a quad-band (850/900/1800/1900MHz) GSM and support 3G networks, HSDPA 7.2. It also equipped with A-GPS, Wi-Fi 802.11 b/g for internet connectivity in the hotspot area, and Bluetooth 2.1 to connect with other devices.
Safari is the iPhone's default web browser. It displays pages similar to its Mac and Windows counterparts. Web pages may be viewed in portrait or landscape mode. It supports automatic zooming by pinching together or spreading apart fingertips on the screen, or by double-tapping text or images.