Apple iPhone OS 3.1 - Manual (Page 85)

Changing the Browse Buttons
You can replace the browse buttons at the bottom of the screen with buttons you
use more frequently. For example, if you often listen to podcasts, you can replace the
Songs button with Podcasts.
Change the browse buttons: Tap More and tap Edit, then drag a button to the
bottom of the screen, over the button you want to replace.
You can drag the buttons at the bottom of the screen left or right to rearrange them.
Tap Done when you finish. Tap More at any time to access the buttons you replaced.
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