How to save battery life on Android phones!! Must have app.
Android: When you're asleep, at an event, or otherwise indisposed, you don't need your battery-draining data connection, but you might still want to take phone calls. Free Android app APNdroid can selectively turn off your data access while allowing calls.
The app's design is a clever one, as activating APNdroid from its app button simply activates the on/off switch for GPRS, EDGE, and 3G networks, allowing you to use the APNdroid icon as a kind of widget on your Android screens. You obviously won't be able to surf the web or sync Google services while your data services are off, or send MMS messages. You will, however, have basic phone functionality, and your battery will probably live a bit longer...