Sony Ericsson on Monday announced the W600, its second "Walkman" phone slated to debut in the fourth quarter. Unlike its W800 older brother, the W600 features a swivel form factor and only 256MB of internal storage.

The company didn't announce pricing, but with a 1.3-megapixel camera and EDGE the W600 likely won't come cheap.

With the W600, Sony Ericsson has removed the MemoryStick Duo slot for external memory, instead focusing on mobile entertainment with 3D gaming. The phone features a 176x220 pixel display that can be turned horizontal when playing games using the five-way navigation key and dedicated A/B gaming buttons.

But music is the true selling point of the W600, with its built-in stereo headset jack and FM radio. The phone supports MP3 and AAC formats, and 30 hours of battery life when only in music mode.

"First imaging and gaming, and now adding music to your mobile phone is the wave of the future. With the W600, music lovers won't miss important phone calls. When a call comes in the music player automatically stops and you receive important calls," said Urban Gillstrom president of Sony Ericsson in North America.

Sony Ericsson also unveiled four new phone models aimed at the lower-end of the market. The S600 sports the same design as the W600, but without the Walkman capabilities. The J210 is a basic phone with entry-level features, while the Z520 is aimed at the more image-concious consumer. Sony Ericsson's 3G addition, meanwhile, is the K608i.