You know what would be a great app, one that combines a calendar app (like calendar pad) and Timerific. This way, when you enter something on your calendar, you can instruct your phone to turn the ringer off during the time of that appt. It would be one stop shopping...make an appt, enter it on calendar, enter time, date, ringer preference (on/off/vibrate)...done
Is there one like it? If you are a developer, have fun.