This is a big one for many people, and we have some fairly surprising news to report. The battery life on the iPhone 4 has been outstanding thus far, exceeding our expectations for longevity during testing. We've only had a short time to use the phone, but in the week or so we've been carrying the device as our main phone, we've had pretty amazing results under normal to heavy use. In fact, we managed to squeeze more than 38 hours -- yes, 38 hours -- of life out of a single charge using the phone as we normally would. We're talking calls, some gaming, lots of push email and calendar invites, playing music over Bluetooth in the car, and just general testing (like downloading new apps, rearranging icons, tweaking settings). We went from 10:30AM on a Saturday morning till 1:00AM on Monday without needing to charge the phone.