Wow!!!
Just kidding, that's cool bro. I don't have the unlimited data plan for the iPhone as I was late to the game but I do have it for the iPad. I barely ever go over 2 GB in a month using the iPad and I don't ever see how I would be able to use that much data on the iPhone.
I used to think that way too but if you buy a lot of tv shows, cd's, movies and apps over 3g you can easily go over your limits