one thing to extend battery life for me on android was background data and auto sync. If you shut that off during the day, you will still be notified of text messages calls (all normal phone operations) what you wont get notified about is email. So if you just go ahead and check for new email when you need to see if you have one, it will only poll the network while you are checking email. If getting emails instantly though was the purpose of the smartphone this wont work. likewise, I was told you can adjust how frequently email polls the network and set it to only check every half hour or so instead of all the time. I can use my smartphone 2 days like that.