The W850i Walkman phone is Sony Ericsson's first slider phone and it's a solid attempt from a company that has previously avoided this form factor. Although there are some niggling issues that we'd like to see addressed in the next iteration, Sony Ericsson hasn't made a complete blunder of the new design.
Standout features include a large colour screen, 3G connectivity and stereo Bluetooth, and a 1GB Memory Stick Pro Duo for storing your tunes. It is available from several networks, free on contracts starting at around £30 per month. It's also available SIM-free from Expansys for about £275.
The top half of the W850i looks a little similar to the K800i. The screen is identical and they have similar speaker grilles and small VGA cameras on the front. The rest of the phone, however, is very different to the K800i, and indeed different to every Sony Ericsson phone ever made.
The W850i is Sony Ericsson's first slider phone, a form factor it has avoided in the past. The top section houses the screen, which measures 32mm by 42mm, and is pleasingly bright so you don't have to shade it with your hand in daylight. The screen changes its brightness depending on the level of ambient light, which is measured by a sensor on the top of the handset. This improves the battery life -- the screen isn't at its brightest setting all the time and therefore doesn't drain as much power.
Next to the sensor is an easy-to access Memory Stick Pro Duo slot for the generously sized 1GB Memory Stick Pro Duo. The power button is to its right.
On the front section of the phone, above the screen, is an ear speaker and a VGA camera for 3G video calls. Compared to the last 3G Walkman phone, the W900i, the W850i is compact and feels comfortable to hold both in the open and shut positions. Like the W900i it comes in dual-tone, although this time Sony Ericsson has opted for graphite and white.
It's easy to slide the top section up and down because unlike many sliders the W850i has a metal ridge underneath the screen for added grip. To the right and left of the ridge are two soft keys that give you access to the call log and menu. In between those two keys and directly underneath the metal ridge is a transparent orange button that takes you straight to the music player. When you press it, it glows orange.
Further down is a four-way navigation key that's disguised as part of the casing, aside from four small dots that light up blue and also turn orange when the music player is being used. In the centre of the four dots is a select key that also doubles up as a play and stop button for the music player.
To the right of the navigation button is a small cancel button and dedicated shortcut menu key and to the left is a back key and dedicated Web browser key. The soft keys are well laid out and easy to press, but the new-look navigation key feels a little cramped. If you have large thumbs, it's easy to press the select key by mistake.
On the right side of the W850i there are two volume keys that adjust the volume during calls and when using the music player. Further down there's a dedicated shutter button that automatically accesses the 2-megapixel camera when pushed. Right at the bottom of the left side there's an infrared port.
The back section of the W850i is textured and houses a 2-megapixel camera with an LED photo light and small portrait mirror. The camera lens is surrounded by a plastic border that does a good job of keeping the lens protected from fingerprints and scratches. We would have preferred it, however, if the camera was protected behind the slide, as it is on the LG Chocolate KG800.
Underneath the camera is a loudspeaker that lets you listen to calls in speakerphone mode and listen to music without headphones. Right on the bottom is a charging port that doubles up as a headphone port and USB port. In the box you get a 3.5mm headphone adaptor, in-ear headphones and a USB cable, as well as a CD of the Sony Ericsson PC Suite software and an AC adaptor.