Apple's new iPhone 4 costs $199

Apple revealed a brand new iPhone at the 2010 Worldwide Developer's Conference - the iPhone 4.

Delivering the keynote address at the highly-anticipated event, CEO Steve Jobs referred to the iPhone 4 as "the biggest leap since the original iPhone", revealing its many enhancements including a fresh design with glass on the front and back, and stainless steel round the sides.

It's also being billed as "the thinnest smartphone ever" at 9.3 millimeters - 24% thinner than its predecessor, the iPhone 3GS, that saw one million units sold less than five days after its launch last year.

The iPhone 4 features a 3.5"display with new 'Retina Display' technology packs in four times as many pixels as on the iPhone 3GS - the highest resolution display ever built into a phone.

Other features include a micro SIM card slot, 'FaceTime' video calling via Wi-Fi with other iPhone 4 users, and a 5 megapixel flash camera that is also capable of HD video recording - all powered by Apple's A4 chip developed in-house and operating the new iPhone OS 4 platform that's been renamed to iOS 4 and boasts over 100 new features. A video, explaining how the iPhone 4 changes the game again, can be viewed here.

The iPhone 4, available in white and black colours, will go on sale in five countries on June 24th - France, Germany, Japan, United Kingdom and United States. Apple will be accepting pre-orders for the iPhone 4 from June 15th with pricing set at $199 for the 16GB model and $299 for the 32GB version in the United States.

The smartphone will be rolled out worldwide to 88 countries by the end of September.