I switched the work smartphone from a Nokia E71 to an HTC Desire. One thing I always liked in the 'business' Nokia phones was the option to switch the 'Profile' for a set time, switching back to the previous profile afterwards. The 'Profile' is the whole of settings for ringtone, vibrate and other notification options. What I used it for was setting a quiet profile at the beginning of a meeting and having it revert back at the appointed time of the end of the meeting. So I wanted this on Android. It was a bit of searching and asking, but I found Llama - Location Profiles which does 80% of the work: switching profiles automatically based on location (mainly using cell towers), time of day, other events. And it can do what I want: stay at a certain profile for a given time.