Apple has just released an update version of iOS, iOS 4.3.1 for iPhone 4, iPhone 3GS, iPad 2, Original iPad, iPod touch 4G/3G. The update is available for download through iTunes on Windows/Mac systems.
The latest update is meant to fix some minor bugs, exploits and battery life issues on all iOS devices.
The changes and bugs fixed in iOS 4.3.1 can be read in this screenshot:
Direct Download Links for iOS 4.3.1 (Official from Apple)