ToySoft just released WiFi_BTPower which lets you simply save battery life. You can setup schedules on your device for when the application should turn Wi-Fi or Bluetooth on or off. This can be a certain time of day on any specific day of the week. For example, you could turn it off when you leave for work during the week and turn it back on when you get home.
The only limitation in the app is that you can have only 64 different schedules. Truthfully if you have more than that I want to know why… WiFi_BTPower is reasonably priced at $1.99 full retail in the store.