Answer to "How to turn off an iPhone 3GS without using the power-button?"Go to Settings on your ipod , iphone ect.. go down to General, then Accessibility, then go down to Assistive Touch. Tap the Assistive Touch ON. Exit Settings and at the bottom right of your screen you will find a round button. Press it to enter Assistive Touch. Press the Device Button on the right. Now PRESS AND HOLD the Lock Screen Symbol until the Power Down Slider appears at the top of the screen. Slide to the right to power off.