Iphone Style

[Kougar]

I have a question that I hope I can get an answer to. I am playing around with themes for my phone using Wisbar Advance and Wisbar Advance Desktop. I have tried several iphone themes and like them all but was just wanting to try to make one myself but am not sure what I need to do to get the sliding effect. I'm not sure if that is something I need to do with Photoshop or what. Any help would be appreciated. Thanks