First of all, Samsung Galaxy S2 is a huge device with loads of features and UI friendly keys. But I found out a bit hard to figure out on how to disable 3G as soon as I enabled it. After some googling I found on how to do it. So I thought of putting this across in the post.
In the Android Marketplace there are probably some widgets you can get for free to turn off the data connection on the phone – it isn’t too obvious out of the box.
Samsung Galaxy S2 front screen
You can drag down the bar at the top of the screen to view the notification area. Here you can disable GPS, Bluetooth and Wireless to save power, but not the 3G data connection.
Samsung Galaxy S2 Notifications screen
I was getting a bit worried that they had left this feature out on purpose in some plot to make me use up my data allowance. They just hid it away a bit.
Press and hold the power/lock button on the right side of the phone to bring up the “Phone Options” window. You can disable data connections here.
Samsung Galaxy S2 Power Off and 3G disable screen