While the new iPhone doesn’t have a screen orientation lock button (like iPad), iOS 4 does allow you to prevent auto-rotation of the screen using a software switch. This is handy in case you want to read a web page or iBook publication while laying sideways on your couch.
- Double-click the home button beneath your iPhone or iPod’s screen.
- In the task manager strip at the bottom of the screen, swipe your finger to the right until you see audio controls and circular arrow pointing clockwise.
- Touch the circular arrow to lock the screen. A lock icon will appear in the middle.
Repeat steps 1-3 to disable orientation locking.

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