Apple has released the software updates for iPhone and iPod Touch users, the update promises to fix

• Decrease in call set-up failures and dropped calls
• significantly improve battery performance
• reduce time to backup to iTunes
• Improved email reliability,
• faster 3rd party application installations
• Improved performance in text messaging
• Faster loading and searching of contacts
• Improved accuracy of the 3G signal strength display
• Repeat alert up to two additional times for incoming text messages
• Option to wipe data after ten failed passcode attempts
• Genius playlist creation

The new iPhone 2.1 Firmware can only be download by connecting your iPhone to the new iTunes 8 so make sure to update it first, but remember that the update will fix [ the jailbreak, incase you did it ], the tool to jailbreak an iPhone on this update version is not yet available.