I'd prefer to run on 3G exclusively as I don't use it for more than 30 mins of browsing a day but due to the icloud syncing and updating exclusively on Wifi, I've concluded that I've got no choice but leave wifi on for the most part. That's fine since I'm at the university and I've got wifi in my house and most parts of the campus but for the times when wifi dips out, how agressive is the phone searching for wifi? I've got it set to don't "dont' ask to join networks" but that wont stop it from polling to see if a known network is in range. In my mind, if it's like 3G then that sould burn a **** ton of power but I'm assuming it's not. How much extra power does it burn when it searches for a signal? Also, how much extra power is 3G + Wifi on going to burn than just 3G on if you use ~ 20 mins of browsing a day. Does the phone turn off the 3G antenna entirely as it's connected to wifi?