Locale is an app that let's you take control of the settings of your phone based on specific conditions that you can choose from. Locale essentially automates all of the functions that you would normally have to switch manually after you configure it to fit your needs.
There are two different areas of Locale that you'll need to setup: Default and Situations. Each one has a series of conditions you have to choose from. They are: Battery, Calendar, Contact, Location, and Time. Each one of these has their own series of options for you to configure. Once you configure the conditions you can move on to the settings tab. In this area you can pair changes and updates to your Network, Ringer Volume, Ringtone, Twitter, and Wallpaper to that specific Situation.
Where situations covers specific instances, default covers everything else. In default you can configure the base settings for Network, Ringer Volume, Ringtone, Twitter, and Wallpaper without worrying about any specific catalyst to set them off.
This is a really great app that makes using your phone a lot easier. You'll definitely need to spend some time configuring everything to just how you want it before you'll truly enjoy this app. After that, you won't even have to think about it until you need to add another situation to your list.