If you are Japanese and owned an iPhone 4s then this iOS 5.1 update is meant for you now Siri will understand and speak your language but what’s new for others in iOS 5.1 update? iPhone 4s Owners will get 3G enable or disable option so now you can choose your network preference. It was not there before which was irritating because 3G consume whole lot of battery if you want to save your battery you was not able to turn off the 3G mode.