Lock the Screen Orientation on the iPad 1, iPad 2, iPad 3, iPad 4
You can lock the screen orientation on the iPad 1, iPad 2, iPad 3, iPad 4 from rotating when the device is shifted in orientation by hitting the Screen Rotation Lock button.
The screen lock button is located on the side of the device, located above the volume controls.
Once you hit that screen rotation lock button, you can rotate the device horizontal or vertical and the screen itself won’t rotate. This is great for reading in bed and for so many other purposes.
This is a handy iPad feature and I wish something similar was available on the iPod Touch and iPhone, anytime I use the thing lying down it’s rotating all over the place making it practically inusable. Thankfully the iPad gets it right!
This applies to the original iPad (iPad 1), iPad 2, iPad 3, and iPad 4. Later iPad models eventually lost the side button, instead moving the screen lock orientation button into the Settings.
[ via Apple ]