I have 2 iPhones on my account. One is a 3G and the other was a 3GS but is now a 4. Since downgrading to the $25 2GB data plan for both phones I've been trying to pay attention to my data usage so I don't go over. June 2010 was the highest data usage ever for both phones and for my new iPhone 4 I am on pace to hit 1.5GB this billing period, around double my highest ever data usage for a month before June. The conspiracy theorist in me jumps to the conclusion that since switching to the new tiered data plan on June 7 AT&T is somehow measuring data differently. I don't use my phone any more than I used to and have recently starting using wifi at home. I just called AT&T to ask what was going on and she said they would put a note on my account. For July 1st and 2nd I've already used 200MB so if that keeps up I'm in trouble for this month. Has anyone else noticed that their data usage is much more than it was before?