Technology had made many things possible. Ten years ago Smart Phones were slide-open and had qwerty key(board)pads. But now, everything changed. We have smart phones that are smarter than us. And they support touch and.. screen orientation.
And the modern web browsers are able to detect when the screen rotates. This is an awesome feature and very helpful for Responsive Web Designers.
But most of the Desktop Web Browsers (as of March 2012) don’t support it. This feature is required in Desktop Web Browsers too. If you are running Windows 7/XP(8?), press Ctrl + Alt + an arrow key. What happened now? Your screen rotated (back to normal by pressing Ctrl + Alt + arrow key up)! So, this works in Desktops too!
There are some browsers that support Device Orientation API for Desktops. So, Web Designers, make use of it!