How to lock and unlock screen orientation on the iPhone 5

If you want the screen to stay in portrait mode while you're lying down in bed or on the grass at a picnic, simply double tap your home button to bring up the system tray. Swipe the tray to the left and you'll see the orientation lock at the far left. Simply tap it to turn it on or off! If you need a little help from Apple's digital assistant, simply press and hold the home button for a few seconds and you'll see Siri's microphone pop up. Tell her to set a calendar event for you or to set an alarm. You can even have Siri reserve tables at restaurants or give you movie times and reviews. If you're unsure what you can ask Siri, simply press the little "i" when the microphone pops up.