MORE: watch our video review of the HTC HD2

The HTC HD2 smartphone is an alternative to, and in some ways an improvement on, Apple's popular iPhone 3GS.

The handset is well-built, thin and light, and its large 4.3in multi-touch screen is the largest we have seen on a phone. The good-looking Sense 3D interface runs on top of the Windows Phone operating system, with a large clock, visual effects and plenty of application shortcuts. It also hides some ugly elements of the Windows Phone interface.

The massive screen makes a big difference when browsing the web or watching video. There is also a GPS receiver that integrates with Google Maps, a Youtube viewer, and a 5-megapixel camera with flash.

These features can be found on other handsets, but they work superbly here thanks to the phone's fast processor. The camera's results are a bit blurry, but images can be sharpened by tweaking the settings, and it can also take excellent panoramic shots.

There is an application for Facebook, one to back up contacts and text messages, and more, with others available online, and a demo of CoPilot Live 8, a turn-by-turn satellite navigation tool.

There are physical buttons under the screen to take users to the home screen or lock the handset, and an on-screen keyboard is used for typing; a nice touch is that the phone vibrates each time it registers a key.

After some practice we found it possible to type quite quickly, but the small keys are difficult for those with large fingers.

The HD2 is not without problems though. The screen is great for video, but its size can make the phone uncomfortable. The operating system can be quirky at times, forcing users to dig through menus to find the task manager or inexplicably locking a file when it’s required.

Battery life was fair, lasting over a day, but that’s slightly less than with other smartphones. Despite this, the HD2 is a decent rival to the iPhone.

The range of applications available is more modest, but aside from a few niggles, anything the iPhone can do, the HD2 can do too, and in some cases it does them better and cheaper.

MORE: watch our video review of the HTC HD2