While its launch wasn’t really a secret, Apple CEO Steve Jobs has finally unveiled the new iPhone 4. While many of its new features are being seen for the first time, most of the specs are very reminiscent of the lost prototype that was leaked online last month.

According to Jobs, the iPhone 4 is the thinnest smartphone on the market, measuring in at just 9.3-millimetres thick. It also incorporates what the company is calling a Retina display and FaceTime video calling.

“iPhone 4 is the biggest leap since the original iPhone,” said Jobs. “FaceTime video calling sets a new standard for mobile communication, and our new Retina display is the highest resolution display ever in a phone, with text looking like it does on a fine printed page. We have been dreaming about both of these breakthroughs for decades.”

Jobs highlighted that the new iPhone 4 will also have a 5-megapixel camera with LED flash, HD video recording, an Apple A4 processor, 3-axis gyro and up to 40 per cent longer talk time.

In terms of design the Retina display has 960 x 640 pixels, which is four times as many pixels as the iPhone 3GS and 78 per cent of the pixels on the iPad. According to Jobs, because the amount of pixels is so dense, the human eye is unable to distinguish individual pixels when the phone is held at a normal distance. This therefore makes text, images and video look much sharper, smoother and more realistic.

The chassis of the iPhone 4 is also quite different from its predecessor. Aside from the slim form factor, the smartphone is made of aluminosilcate glass, which is chemically strengthened to be 30 times harder than plastic, more scratch resistant, and more durable.

The front and back glass also features an oil resistant coating and the stainless steel band is made of a custom alloy that is five times stronger than standard steel.

The new Apple iPhone 4 features the new iOS 4 operating system and includes over 100 new features including multitasking, folders and advanced mail.

The iBook app and iBookstore which was recently released for the iPad will also be available on the iPhone 4. This is in addition over 225,000 apps already available on the App Store.

In terms of battery life, the phone delivers seven hours of talk time on 3G, up to 10 hours of web browsing on Wi-Fi and up to six hours on 3G, up to 10 hours of video playback and 40 hours of audio.

It will be available in Australia by the end of July. Pricing has not been released.