So, I recently updated the software on my iPhone 4 from 4.3.1 to 4.3.2 and set up as a new phone. I can say that this has effectively solved my battery woes. I have gotten 3.5 hours of usage and 15 hours standby time so far and I'm only at 75%! WOW. I should mention that I virtually have everything on - 3G, wifi, location, push notifications and mail with 4 accounts (did disable Ping and YouTube app, though). I should also mention that I'm jailbroken and running Winterboard, and that I calibrated the battery until the iPhone shut off and charged it fully with everything off (airplane mode, all JB tweaksand push notification and email off). I just thought I'd share just in case anyone was still experiencing bad battery life and wanted to try this for themselves or pass it on to others who may not view this forum.