Over the past year, I have been working on a new application, Location ringer. Location Ringer allows you to create location based ringer profiles called Ringers.
Ringers allow you to have your phone automatically change basic settings based on where you are. For example you can have your phone automatically become silent when you go to work, or automatically enable your WiFi when you get home.
I have been using Location Ringer over the past year with great success.