Sharp-shooting new arrival

The iPhone 4 includes a raft of new features not found in earlier models such as the ability to shoot and edit high-definition quality video and a crisp higher-resolution screen.

It is thinner, has better screen resolution and adds a front-facing camera for video conferencing. It also sports a new type of glass and a stainless-steel band Apple says is designed to improve reception.

Apple chief executive Steve Jobs said the higher-resolution screen was a major leap forward.

"There has never been a display like this on a phone," he said at the launch.

The 8.9cm screen is the same size as on previous models but features 326 pixels per inch, four times more pixels than the earlier iPhones.

"There is a magic number around 300 pixels per inch, that is the limit of the human retina," Jobs said. "We are over that limit."

He said an improved battery gave 40 per cent more talk time.