Ok so I am trying desperately to figure out by the first of august when I am eligible for a new iphone if its at all possible to do pay per use internet.

So theres posts like this:
Quote Originally Posted by Bearxor View Post
Yes, you can. The absolute best way to do this is to buy a used phone and have the IMEI attached to your account.

Just call up and say that you didn't like the iPhone and wanted to switch down to a regular phone. You could probably go in to an AT&T store to have this done as well. While they're changing your phone over, simply say you don't need the iPhone data plan anymore, but would like the internet on your device still, and they'll sign you up for the MEdiaNet plan for $15/mo.

Wait until they're done, make a call from the phone so you know it works properly, then pull the SIM and put it in your iPhone. You will lose Visual Voicemail by doing this though. It depends on how important that is to you.

People on HoFo and XDA do this all the time. Just keep the other phone around in case you have to call in and for some reason they ask for your phones IMEI.

AT&T does have a way to check IMEI's of phones being used at the tower level, but they don't. They run regular sweeps through their billing system to make sure the proper data plans are attached to the proper phones, but this only checks the IMEI they have registered in their billing system with your data plan, not the phone you're currently connecting to a tower with.
-http://forums.macrumors.com/showpost.php?p=6111493&postcount=24

then theres posts like this:
Quote Originally Posted by bruinsrme View Post
I did a little test.
I bought my son a 3Gs on launch day Friday june 19.
The following tuesday we met for lunch. I pulled up my ATT and it showed his phone as some samsung. We swapped the SIM into the new iPhone and one we had bars the page was refreshed, so was his phone. It showed he was using an iPhone just like that.
-also Mac Forums - View Single Post - Can I use AT&T Media Net Unlimited for iPhone 3G?

So all in all here is my final question. How does ATT data sweep work? Can they tell your IMEI number in their sweeps? Is it possible to attach an IMEI to an account then take out the sim and put it in an iphone? Also is ATT following up on these threatening messages saying they are gonna add the $30 data plan? Please any help would be great! Thanks!!