Apple chief executive Steve Jobs on Monday unveiled the fourth generation iPhone, the iPhone 4G, at the Worldwide Developers Conference in San Francisco:

The iPhone 4G comes with a faster processor, a 3.5-inch display with a resolution of 960 by 640 pixels and a dual camera 5megapixel camera that can shoot HD videos also.

The battery of the latest version of the iPhone offers up to 7 hours of talk time over the 3G network. The iPhone 4G supports 2G, 3G and 4G networks. Thus, a person using the phone to talk over the 2G network gets a longer talk time.

Steve Jobs had claimed that iPhone 4’s display had a pixel density of 326 pixels per inch. He added that this resolution exceeds human retina that has 300 pixels per inch for a display around 12-inch away.

But according to the president of DisplayMate Technologies Raymond Soneira, Mr. Jobs’ claim that iPhone 4G has a retina display were inaccurate. However, he admitted that the iPhone 4's display is the best mobile display available so far.

In the UK, the iPhone 4G will be available on a number of networks including O2, Orange and Vodafone. Networker providers are offering customers with a chance to buy out existing contracts and switch over to an iPhone 4G immediately after its UK launch, but analysts have warned that customers should be aware of hidden costs.