Apple has released iOS 5 beta 6 for developers . iOS 5 beta 6 ipsw is now available for iPhone 4 GSM / CDMA 3GS iPod Touch 4 3G , iPad 1 and iPad 2 . If you have a $99 developers account in Apple.com , go here and download this beta build .
Apple has stopped Developers from pirating iOS 5 beta firmware and deactivated those accounts who were caught in the act. Hence it is advisable that you get a legitimate developers account and download iOS 5 beta 6 ipsw from there .
You will also need iTunes 10.5 Beta 6 to install and activate your iPhone on iOS 5 beta 6 , which also available at the developers website . Also Read More about iOS 5 Firmware Features .