Apple has released a new firmware for the iPhone and iPod Touch. This new firmware is labeled 3.1.3. What is different in OS 3.1.3 are as followes:

• Fix for iPhone 3GS battery level reporting
• Fix for app crashes on launch
• Fix for app crashes while using Japanese Kana Keyboard

To get the 3.1.3 update just connect your iPhone or iPod Touch to iTunes, download the firmware and install.