I was just going ask how you are using so much data, but then I figured if I should ask if you are using WiFi at all?
I actually am using wifi, that's what's sad. Every time I'm at my apt, the first thing I do is connect to my wifi signal. I think since this is my first android phone, and I just got it a little over a week ago, I'm using it almost non-stop. I'm sure eventually my data will go down, but right now I use Pandora pretty often, the Youtube app, I have various widgets that use data as they update, and I'm browsing the internet quite a bit. Plus, since I just got this phone, I'm always in the market downloading apps. I probably need to go through my various apps to make sure they're using wifi when available.