iOS 5.1 brings back the option to disable 3G
new features in iOS 5.1 include Japanese language support for voice activated personal assistant Siri, movie support in iCloud and a permanent camera shortcut for the lock screen. The camera's face detection feature now highlights all detected faces. And besides adding the option of disabling 3G connectivity to increase battery life, iOS 5.1 also fixes some bugs related to the battery.
For those rocking their Apple iPhone over AT&T's network, iOS 5.1 also replaces the 3G icon with a 4G one. This does not mean that your Apple iPhone 4S has magically become a 4G phone overnight. We have previously explained the reasons why the AT&T variant of Apple's smartphone is technically not a 4G device. And if you don't see the disable 3G option on your iPhone, it means that you haven't yet installed iOS 5.1. You can do that by using the Software Update function on iOS or by hooking your iPhone to iTunes via your computer.