More than 1.7 million of the iPhone 4 sold

The new iPhone has a range of new features, such as FaceTime video calling over Wi-Fi,a new retina display with the highest resolution ever built in a phone, and a 5 megapixel camera complete with LED flash.

It also carries a new industrial design, an A4 processor and a 3-axis gyro. It’s new iOS4, its new version of the iPhone operating system, which has multitasking, folders, enhanced mail and better enterprise report.

“This is the most successful product launch in Apple’s history”, said Steve Jobs, Apple’s chief executive. “Even so, we apologise to those customers who were turned away because we did not have enough supply”.

People who have pre-ordered in the UK will end up getting their new iPhones later than the original launch date due to these supply problems.

"It's amazing how the fourth iteration of a product could generate the longest lines and the strongest sales yet," said Walter Piecyk, an analyst at BTIG Research.

Other solutions could be to go to a network operator to buy one, although Apple is the only place that you will be able to get a sim-free unlocked device.