The most distinctive part of this phone is the back side. Just like on certain series of digicams, the camera lens and LED flash are revealed by sliding down a cover that occupies almost the whole back of the phone. This cover has a decorative silver stripe running across the middle of the phone when closed.

This active sliding mechanism is very smooth and it immediately starts the camera. There is a slight resistance when starting to slide down the cover, but after the mid-point it goes down all the way almost automatically. Thumbs up for both looks and handling here.

The sleek and ingenious rearside of the C903 has digicam looks

Removing the battery cover unveils the standard Sony Ericsson BST-33 Li-Po battery with a capacity of 1000 mAh. The same unit is widely used across a range of Sony Ericsson handsets.

The manufacturer claims the battery should provide up to 400 hours of standby and up to 10 hours of talk time in a GSM-only network.

In reality, battery life ranged over two to five days on a single charge, depending mainly on GPS and multimedia usage.

Sony Ericsson C903 powered by a standard Sony Ericsson BST-33 Li-Po battery

The Sony Ericsson C903 is a compact and distinctly styled slider. Ergonomics are just fine and we hope the minor handling issues are easily fixed before the phone starts shipping.

Sony Ericsson C903 held in hand

Display: Good, above average

The Sony Ericsson C903 employs a 2.4" 256K-color TFT display of QVGA resolution and it is said to have a scratch resistant surface. Though the same size and resolution as the C905 display, the two screens are quite different in terms of color and reflections. The superior mineral coated display of the C905 is extremely low on reflections and has superb clarity and contrast while the display of the C903 is more reflective resulting in less vivid colors. Regardless, it's still one of the better displays on a Sony Ericsson phone. Sunlight legibility is excellent, even under direct sunlight. We have no problems with either reading or typing using both dark and light themes.

The C903 display performs very well, thought not quite in the same league as the C905

User interface: no news is sometimes good news

The C903 interface is the regular Sony Ericsson feature phone UI that is used in most of their top handsets. To say it straight, the C903 offers nothing than a few cosmetic tweaks over the year-old C902 - except for the new threaded messaging of course. It's also true though that it doesn't fall short of the Cyber-shot top dog C905.

The standby screen is arranged in the usual manner with information on top indicating signal strength, currently used data carrier and battery status. At the bottom of the display, just above the context keys are their labels.

The well-known Sony Ericsson home screen

The options for the menu layout are the standard foursome - theme-dependent, 3 x 4 grid of icons, rotating view and single icon view.

Setting up the menu layout

The rotating view features three animated front icons on the display, the center one showing the active selection. The other two icons are half-hidden, just as an indication of what comes next. Five other menu icons can be seen in the dim background.

The icon view displays a single icon at a time and a vertical bar featuring tiny icons for the other main menu entries. Neither of those view modes works with shortcut keys. Only the Grid view allows quick numeric keypad access.

The two alternative layouts

The well-known Activity menu offers quick access to a user-defined list of favorite features, web, recent events and, of course, the Running Apps tab that takes care of multitasking.

The well-known Activity menu

You can minimize the progress indicator when receiving a file over Bluetooth but you can't do that when sending a file.

Flight mode can only work with a SIM card in the device and requires a restart.

The interface is visually appealing and snappy. Auto rotation is enabled in the Media Center and is generally quite responsive. There's a hardly noticeable lag involved but we guess that's to be preferred over an over-sensitive accelerometer that can often play up.

Sony Ericsson C903 supports Flash Lite themes, which change the color scheme and wallpaper. Our handset has five themes preinstalled: Amber, Amethyst, Azure, Borderline, and Clarity.

Amber theme

Amethyst and Azure themes

Borderline theme is a bit too much to our taste

Sony Ericsson handsets also come with a handy option for their wallpaper - you can use an application as a background instead of an actual image. Of course you can't just use any application - the choice is currently limited to one of out of only three apps. These are WalkMate, Slideshow Wall and Rock Bobblehead. The step counting WalkMate is probably the only practical app among them.