Sony Ericsson has announced four new phones today including its latest Walkman handset the W850i. The new phone is the company's first GSM/3G "slider" model.

Available in Precious Black or Golden White, Sony Ericsson has even included a "heartbeat illumination" feature to light-up the control keys in rhythm with your music.

Pushing the music element of the phone, Sony Ericsson has also included a 1GB memory stick PRO Duo in the box, which is enough Sony Ericsson say for around 1,000 songs in the e-AAC+ format. The phone also supports MP3, AAC, AAC+, eAAC+, m4a playback and the phone will take a MS PRO DUO card up to 4GB meaning it will match Apple's iPod nano for storage.

In addition to the new phone, Sony has included the latest version of its Walkman player software, version 2.0 and this promises simplified navigation through music genres, playlists, individual songs or music albums. There’s also a TrackID feature powered by Gracenote Mobile MusicID.

This is a new service which means you can record a few seconds of a song, either via the microphone or the in built FM radio, and then with one click, send that clip to the Gracenote worldwide music database which will identify the track and relay the information back to the phone.

Get past the music and Sony has included a 2 megapixel digital camera with 4x digital zoom, a 2-inch QVGA 262k colour screen, web browser, Bluetooth and Tri-band connectivity.

It is commercially available in Precious Black or Golden White and starts
shipping during Q3 2006.