Sony Ericsson has used the Mobile World Congress event in Spain as the launch pad of the "XPERIA" range that they say heralds a new era in mobile communications and has announced the X1 model, a new "arc slider" phone.

Designed to meet the growing need for mobile web communication and multimedia entertainment (or to stand up to Apple's iPhone) the company says the range will offer a "premium, converged mobile experience".

The XPERIA X1 combines a 3-inch wide touchscreen VGA display and a full QWERTY keyboard, a 4-way key and optical joystick navigation within a metal-finish body.

Running on the Windows Mobile platform, a first for the company, the phone has been specially tailored for Sony Ericsson with access to features via the customisable "XPERIA" panel on the touchscreen.

The "arc" design means you slide the screen sideways to reveal the wide pitch QWERTY keyboard that it said to have "ample" distance between keys makes writing fast and easy.

Connectivity comes in via HSDPA/HSUPA and Wi-Fi support while aGPS provides navigational functionality.

The Sony Ericsson XPERIA X1 will be available in selected markets from the second half of 2008.