The iPhone 4 uses a microSIM card, has a new forward facing camera, as well as a unique integrated antenna system that puts the antennas along the exterior edge of the phone's body. The left side of the phone's stainless steel outer casing is home to Bluetooth, WiFi, and GPS antennas while the right side houses the UMTS and GSM antennas. The phone also has a glass front face and a glass rear face, and both panels are scratch resistant and offer better optical quality. The side of the phone is also home to volume keys and a mute button. The top of the phone offers a second microphone for noise cancellation, a 3.5mm headphone jack, and a sleep/wake power button.

The display on the iPhone 4 uses a new "Retina display" technology that improves the sharpness of text and images on the screen for easier viewing by displaying 326 pixels per inch. According to Apple, when 10 to 12 inches away from the screen, the human eye can't make out individual pixels on this display. The Retina display offers a 960 x 460 resolution with an 800:1 contrast ratio, and uses In Plane Switching (IPS) technology that Steve Jobs says is preferable to the OLED displays currently in demand. Despite being a 3.5-inch screen, it has 78 percent of the pixels that the iPad's 10 inch display does.

The iPhone 4 is powered by an A4 processor designed by Apple and has a large battery that Jobs claims is good enough for up to 7 hours of talk time, 6 hours of 3G browsing, 10 hours browsing over WiFi, 40 hours of music, 10 hours of video playback, or over 300 hours of standby time.

In terms of connectivity, the iPhone 4 has quad-band HSPA(INFO) 3G network support that is good for a theoretical 7.2Mbps download speeds or 4.8Mbps of upload speed. It also has 802.11n Wi-Fi connectivity, a compass, and an accelerometer. Apple has decided to add a 3-axis gyroscope sensor, as well, which will offer six axis orientation sensing for gaming when paired with the accelerometer.

The new iPhone 4 also includes a 5 megapixel camera with a backside illuminated sensor that allows more photon to reach the sensor. It also has a tap-to-focus autofocus system, 5x digital zoom, and an LED flash. The camera is capable of recording video in HD at a 720p resolution, and the iPhone has built-in video editing software. Apple also announced iMovie for iPhone, which will be available for $4.99.

The phone will run iOS 4, which is a renamed version of iPhone OS 4. The OS will support folders, as well as multitasking. It includes 1,500 developers APIs and 100 new features for users. iOS 4 also includes a unified email inbox as well as message threading. To create a folder, a user simply has to drag one app on top of another.

Jobs also said that iOS4 has deeper enterprise support, which includes SSL VPN, Exchange Server 2010 support, and better security features for data and device managem