Apple iPhone 4

MORE: Click here to see our overall video review of the iPhone 4

Click here to find out about Facetime video calling

The fourth version of the iPhone departs from the look of the earlier models’ design. The rounded case has gone, replaced with squared-off edges (although the corners are still rounded) and a stainless steel band that rings the case.

The band serves several purposes: it includes all the phone’s aerials, as well as being the main structural support for the phone’s body – all of the rest of the phone is attached to the stainless steel frame.

The glass touch-screen remains on the front, but the plastic back has been replaced with another glass panel. This looks good, but it does make the phone more susceptible to damage when it’s dropped. That makes buying a case (Apple’s ‘bumper’ case costs an eye-watering £25) an imperative.

The screen has been vastly improved, with the new one among the best available on a phone. Its resolution has been doubled, which makes text sharper and images clearer, and the contrast has been noticeably improved.

Inside the phone, the main improvement is to the processor and memory. The processor in the iPhone 4 is faster than those in previous models and moving from a 3G model to the new one, we noticed a big difference in everything from starting the phone to web page loading times (which are largely dependent on your internet connection but also to a surprising extent on the phone’s processor and memory, the latter having also been upgraded).

The phone runs the latest iPhone operating system, now called iOS 4, the main difference being the addition of Folders. If you have lots of applications they can now be combined on the phone’s home screen into folders, making for better organisation and easier access.

As well as the camera on the back (which has been upgraded to five megapixels and now comes with a small flash) there’s a camera on the front of the phone too, enabling what Apple calls Facetime and the rest of us know as video calling. It only works with other iPhone 4 users, which is a shame, but when we tried it, it worked well. Annoyingly, you need to be connected to a wireless network to use it, which limits it considerably. The phone can shoot high-definition video at a resolution of 720p.

A gyroscope has also been added, which gives the phone better awareness of its motion. We’ve yet to see applications making much use of this, however.

With all those features, you might think battery life would suffer but our tests indicate slightly improved battery performance over the 3GS. For medium-heavy use charging it once every two days will still be essential but that’s roughly standard for a modern smartphone and better than the iPhone 3G.

If you’re coming to the iPhone for the first time, the iPhone 4 is an excellent place to start. It remains easy to use, and the speed increases and screen improvement make a real difference. People upgrading from a 3GS might not see much of a boost but the gap between this and the 3G is certainly noticeable.

The iPhone 4 is expensive, at £600 for the 32GB model unlocked for any network, or, to pick a network deal at random, £349 plus £20 a month for the cheapest 16GB iPhone 4. If it's a smartphone you're after, it’s worth it.

MORE: Click here to see our overall video review of the iPhone 4

Click here to find out about Facetime video calling