As announced by Steve Jobs at the "Let's Rock" special event earlier this week, Apple has released the iPhone 2.1 firmware.

The iPhone 2.1 software update contains many bug fixes and improvements, Apple says.

As well as the well-publicised "Genius" playlist creating feature, the software offers the following:

* Decrease in call set-up failures and dropped calls
* Significantly better battery life for most users
* Dramatically reduced time to backup to iTunes
* Improved email reliability, notably fetching email from POP and Exchange accounts
* Faster installation of 3rd party applications
* Fixed bugs causing hangs and crashes for users with lots of third party applications
* 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

To install it users need to upgrade to iTunes 8, if they haven't already and then connect their iPhone and click "Check for Update".