After years making phones based on the Symbian OS, Sony Ericsson has just taken a major step in a new direction by unveiling its very first device with Windows Mobile.

"Our vision for the Xperia X1 is to deliver a seamless blend of mobile web communication and multimedia entertainment within a distinctive design," said Rikko Sakaguchi, head of portfolio and propositions, Sony Ericsson. This smartphone will include a 3-inch WVGA (800 by 480 pixel) display that can slide aside to reveal a QWERTY keyboard. Other navigation options will be a four-way key and an optical joystick. The X1 will be a quad-band GSM phone with support for the 3G frequencies used around the world. It will also have Wi-Fi and Bluetooth. This Windows Mobile Professional device will include up to 400 MB of internal storage, plus a microSD card slot. In addition, this model will include aGPS, a 3.2 megapixel camera, and an FM receiver. It will be 4.3 inches wide, 2.1 inches tall, and 0.66 inches thick (110 mm x 53 mm x 16.7 mm). It will weigh 5.1 oz. (145 g). Sony Ericsson says the XPERIA X1 will debut in the U.S. in the second half of 2008. The company is not yet willing to say what this model will cost. More information on this smartphone can be found on its maker's web site.