I'm currently using an iphone 4, and before that an android. With both devices I've always fretted about battery life. I've been with iphone 4 for a few months now, and only now realized I could see my usage amounts. It seems I'm getting about 5 hours of usage/16 hours of standby. I'm at around 30% brightness, 1 hour of podcasts a day, 50-100 text mesages a day, and minimal web browsing or other use. Early on I read an article on battery saving tips and implemented most of them. Normally I'm at home, and when I go out, it's generally within a couple of miles of my house. So, what does this all mean, and how might things change when, say, I travel tomorrow on a train from New York to Boston, and spend the weekend up there? What kind of things affect usage and in what ways? And how is usage even measured -- the amount of time the screen is on or something? Enlighten me, please, folks.