A Finish guy created a script for iTunes to upload songs to the SonyEricsson Walkman phones with iTunes.
iTuneMyWalkman is an iTunes script that will help you synchronize the contents of iTunes playlists with you Sony Ericsson Walkman phone. The playlists can be either regular or smart ones. The script can also automatically detect when you connect your phone, and will ask you if you want to synchronize. When the files have been copied, you can Eject the phone.