If you haven't looked at Tasker, check it out. It's priced in Pounds; when I pulled the trigger the exchange rate made it ~$5.
Basically tasker it's a macro system that can automate most functionality of the [Android] phone. When any given macro exits the phone settings are reset to their original values unless you specifiy otherwise.
Examples from my own usage:
Silence during meetings: watch the Google calendar. When starting an appointment marked "Busy", turn phone to silent mode.
wifi battery conservation: even when wifi is turned off, scan briefly every X mins to check if near a specified wifi access point. If nearby, turn on wifi, connect, and turn on auto-sync. Disconnect when leaving the area.
Same for celltowers, gps, etc. Name your poison.
This may be particularly important for folks that are too
To give you an idea how clever this stuff is: if you pick more than one location type Tasker starts with the lowest-power-consuming one. For example, a celltower + WAP requirement would use celltower first for a power-inexpensive sanity check to see if you are in the general
area, and only then trigger the battery-hogging wifi for fine-grained checks. So if you never get within celltower visibilty of the target the wifi check is never activated. Good stuff, Maynard.
Find missing phone: when receiving an SMS from a given number with a given string as the
message, turn on GPS, get a lock, and SMS back the coords, battery level, etc. This functionality is $99/yr for iPose users.
Podcast listening: when I connect with one of my named BT headsets it brings up an app that streams normal audio over BT. When I connect with a different, A2DP-enabled earpiece it dooesn't run that app because a2dp handles that duty.
Night mode: turn off wifi, bluetooth, and phone between 1-5am since I'm not going to answer
it anyway. Saves battery if I forget to cable it up for the night.
Power conservation: when on power cord turn on all the power-expensive toys you want;
bright screen, gps, wifi, 3g, whatever. Or maybe only turn them on
when the batt is fully charged, so you get fastest charge possible and then get the fun stuff.
Low battery: when below 20% battery, disable 3G and autosync, disable wifi+GPS,
turn screen to minimum, say the arbitrary words "arrrrghhhh, low on
battery!" or play a particular sound or whatever.