Possible to do AT&T prepaid plan without GoPhone (want to use my own iPhone 4)?

I'm currently on T-Mobile and you know how it is with iPhone… Only 2G and no 3G data. I'm done with my contract and need to use the phone for 5 more months so I don't want to sign up a 2 year contract.

I'm going to restore my phone back to factory state and want to sign up for AT&T prepaid plan but is it possible to do it w/o buying the GoPhone?

Yes you could.

Buy a regular sim card. Activate it online with a gophone plan.

Here's a IMEI # you can use - 012599001753786

(Do not use your iphone's imei when activating the sim)

After you activate the regular sim card, print out a sim card-to-microsim cutting measurement and trim the sim down to micro size. Then insert it in your iPhone.

You won't be able to use prepaid data by default. But if you change your iPhone APN settings then it will allow you to use data. You can get the APN settings instructions easily with a google search.