Can you shut off the iPhone 4 without the sleep/wake button?

From ->http://grownupgeek.com/how-to-turn-off-iphone-without-power-button

"How to turn off an iPhone with no power button or a broken power button (no jailbreak):

Enable Assistive Touch: Tap SETTINGS, General, Accessibility, AssistiveTouch (near the bottom) and tap AssistiveTouch to ON. You will now notice a small dark square with a circle in the middle (you can move this square anywhere). Tap the dark circle to open the assistiveTouch menu, then tap Device and tap and HOLD the Lock Screen icon. This will bring up the iPhone's Power-Off slider - no need for a power button any longer!"