When the iPad first shipped the side switch — the one found just above the volume rocker — was for locking the orientation. Meaning, if the iPad was upright in portrait mode then you could toggle the orientation lock and move the iPad around every which way and it would not auto rotate the orientation of the screen.

In iOS 4.2 Apple changed the orientation lock to become a toggle for “silent mode”. Like it is on the iPhone. Toggling silent mode only affects the system sounds, such as keyboard “clicks”, the new email tone, and now (on iPad 2) incoming FaceTime calls.

In iOS 4.3 Apple added a Settings option which allows us to choose what we want to toggle with that side switch: lock rotation or mute system sounds. You can adjust that setting to suit your own needs by going to Settings → General → “Use Side Switch to:”.

Up until yesterday I have been using the side switch to mute system sounds. I very much like having the system sounds on — I enjoy the click-click sound of when I lock and unlock my iPad; I type better when I can hear the tapping sound while typing on the software keys; I like the sent mail notification sound since the emails are usually sent in the background.

But, there are times when I don’t want the iPad to make noise on it’s own. Such as when new emails arrive or when there are iCal alerts.

One way to mute the iPad is to hold down on the volume rocker for about 2 seconds. But this only works when the iPad is unlocked. When it’s locked the only way to mute system sounds is to unlock it and hold the volume rocker, or use the side switch to toggle system sounds.

Though I read on my iPad more than any other activity, I rarely need to lock the orientation. It’s not often that I am lying on my side with the iPad in landscape mode yet reading with the orientation locked in portrait. And so I’ve kept the side switch option set for muting and un-muting system sounds.

After posting about this on Instagram/Twitter yesterday I got a ton of responses on Twitter from people telling me I was out of my mind.

This morning I spent a few minutes poking around in the System preferences for sounds and I discovered some very helpful settings:

In Settings → General → Sounds I found that I can turn off the exact notifications which I don’t want to play when the iPad is locked — the new mail alert and the calendar alerts — which solves the very reason I was using the side switch for muting system sounds in the first place. So, yes, it now makes sense for me to use the side switch for rotation lock.