I came to this forum just to post this exact idea.

I'd like it for the following situation: I use a generic "Meeting" setting for meetings at work, movies, etc which puts the phone on vibrate and changes my GTalk setting to Busy/"In Meeting". The problem is that I often forget to un-set it at the end of the meeting, and then e.g. nobody chats with me for hours.

I've kludged this by using the wallpaper feature to choose a garish red wallpaper, to remind me that I need to change things back, but I'd prefer something a bit more subtle.