No no no no man.......This is what you need....and best of all it's already readily available!
Swcked Phone Suite. Profiles.
The necessary profile can be selected from the Today plug-in in just a couple of taps or button presses.
You can also activate a certain profile only for a specified time interval. Just set the Silent profile before the important meeting for half an hour and you won't forget to return to normal mode as you may have done before!
Click here and see where I already have this posted on Wckediden for free!!!