The iPhone 4's brand new design has glass at the front and back, and it's the same glass that helicopter windshields are made from, which is 30 times harder and 20 times stiffer than plastic. The iPhone's structural strength is enhanced by a stainless steel band, and, at just 9.3mm, it's the thinnest smartphone in the world.

The iPhone 4's processor is the iPad's A4 chip, which clocks a cool 1 GHz, while being amazingly power efficient. It allows 7 hours of talk time or 6 hours of browsing on 3G, 10 hours of browsing on WiFi, 10 hours of viewing videos, 40 hours of playing music and 300 hours on standby.

The iPhone 4 has a 3.5-inch 'Retina Display', which boasts a resolution of 960x640, better than any mobile currently on the market, with 4 times the contrast of the iPhone 3GS. At 326 pixels per inch, it's too high for the human eye to see the pixels in it. The 5-megapixel camera has an LED flash, and a front facing camera for video conferencing, plus you get 720p HD video recording with built-in editing.

The iPhone 4 can be hard reset to its factory settings, using a PC and iTunes, like its 3G predecessor. It has a host of great features, such as a 3-axis gyroscope, dual mic suppression, gyro + accelerometer to provide 6-axis motion sensing, compass, proximity and light sensors, a 3.5" mm jack and micro SIM tray, as well as the astounding, feature packed iOS 4.0.

Can't afford the new iPhone 4? Recycle your old mobile!