I just activated my ATT 3G for the first time and wanted to document the auto renew opt out procedure. I signed up on a PC at https://buyasession.att.com - When you give it your credit card info etc, it clearly states that you will be auto renewed every 30 days unless you cancel. There was no option to opt out of auto renew displayed on the screen. I was concerned so I called ATT and spent half an hour on the phone with them. The good news is that you should just go ahead and complete the transaction. When it's done, you can go into your Account Information screen under "My Devices and Plans". Look on the bottom under Purchase History - there's an entry for "enrolled in Auto Renew?". There's a link to "edit plan info" that will allow you to change the "yes" to a "no".