First we showed you how to add the multitouch gestures to an iPhone 4 running iOS 4.3 beta, and today we’re going to show you how to make your iPhone more like the iPad by adding hardware rotation lock.
1. Jailbreak iOS 4.3 beta ( here’s a nice tutorial )
2. Download .plist files
3. SSH into your iPhone and browse to /Applications/Preferences.app/ and backup general.plist and settings.plist. Now over-write them with the ones you just downloaded
4. Go to /var/mobile/library/preferences/ and edit com.apple.springboard.plist. Add SBUseSystemGestures as a key and set it as true.
5. Go to System/Library/CoreServices/SpringBoard.app/ and edit N90.plist. Add multitasking-gestures as a compatibility and set it to true.
6. Reboot and enjoy. Now you can use your mute ON/OFF switcher on your iPhone as a rotation lock.