Today Apple launched a new version of the OS for iPhone and iPod touch. It’s the 3.1.2 version and the most important fixes are:
• Resolves sporadic issue that may cause iPhone to not wake from sleep
• Resolves intermittent issue that may interrupt cellular network services until restart
• Fixes bug that could cause occasional crash during video streaming
If you hook up your phone in iTunes it will find the 250 MB update.