My old iPhone broke a couple weeks before the iPhone 4 came out, so I used an old BlackBerry in the interim, which caused me to lose my unlimited plan. I never used 3G much on the old phone (jailbroken, turned 3G off using BossPrefs usually) so I opted for the 200 MB plan this time around. Turns out, I went over about 200 MB the first month. I was very conscious of my usage, (which was, I thought, very light), and kept 3G turned off when I wasn't using it to prevent push notifications or whatever from eating it up. Now, I've switched to the 2GB plan, and I'm wondering: Is that enough to keep 3G on all the time and get notifications from Facebook, email, etc. without worrying too much? Also, my phone says I only used 151 MB of data last month (so does the AT&T app), whereas my bill says I used 408 MB. Is there a way to explain this?