Nokia isn't the only mobile phone maker announcing new models ahead of the CeBIT electronics conference in Germany next week. Sony Ericsson has unveiled four handsets, which include the company's first Walkman-branded phone that sports a built-in music player, and bundles a 512MB memory stick and headphones.

The Walkman phone, or W800, was first announced at 3GSM earlier this month. It supports MP3 and AAC audio files, which can be played in a music mode even when the phone is off. Software will be included to easily transfer tunes from a computer.

In addition to its music capabilities, the W800 offers a 2-megapixel camera and personal information manager. Sony Ericsson is touting a 30-hour battery life, but only in music mode.

"We looked carefully at what people want from a mobile digital music player and have designed a product that fits the bill," said Rikko Sakaguchi, Sony Ericsson Senior Vice President. "The W800 has great sound quality, is easy to use, has superb battery life and can store a large amount of music."

Other new handset models announced by Sony Ericsson Tuesday include the K750, a 2-megapixel camera phone with auto-focus, along with the lower-end K300 and J300 phones.