Alarms are the only events I am aware of that produce sound while the mute switch is set to on. There are no settings in iOS 5 or 6 to change that behavior. So basically you have to make an alarm to do what you want.
Sadly, Android handles this entire situation better with the ability to set 7 different sound levels (that I am aware of, they may have added more in 4.x) and the ability to run an App that even controls when to adjust those volumes so you can create very custom Do Not Disturbs.
