Sony Ericcsson w580i Walkman Phone : Shake it up but How ?

Well not long ago but yesterday I bought a new Sony Ericcsson w580i Walkman Phone. Hritik Roshan is a brand ambassador for Sony Ericcsson phone in India. He can be seen shaking up W580i and W910 phone to change the track. Although it look funny shaking your new phone as you got a faulty piece. Nevertheless I tried to shake it to change the track on my walkman application but it never worked. Checked manual and official website but there is no mention about how to turn on this feature. After some fiddling I found that I have press the walkman button and shake a little to change the track. Atlast I got it right before it got slipped out of my hand shaking it up and looking silly.