Apple has seeded iPhone OS 3.1 to developers for testing  and development purposes. The main improvements in this update are:

• Video editing on iPhone 3GS wont overwrite the clip over the original when you are editing a clip.
• iPhone will now vibrate whenever you switch to the mode where you can move and arrange icons on the iPhone home screen.
• “Fraud Protection” toggle has been added to settings under Safari.
• iPhone boot time is now faster.
• Voice Control over Bluetooth.
• New APIs to enable third party apps to access videos and edit them.

This version should also fix the performance bugs that many iPhone and iPod Touch users have been reporting. Along with the the fixes and improvements, iPhone OS 3.1 will also improve battery life on the iPhone 3G S as well which should come as a nice surprise for the early updaters to the new iPhone.

The iPhone 3.0 update was released on 17th June for the iPhone, iPhone 3G and iPod Touch and comes preinstalled on the iPhone 3G S. It brought new features such as MMS, copy paste, landscape keyboard, spotlight search, Internet tethering, Automatic Wi-Fi login, Stereo Bluetooth, parental controls and many more.