Are you an AT&T iPhone veteran who misses your unlimited data plan? Try sweettalking customer service.

Thanks to an "unadvertised loophole," as the Associated Press calls it, AT&T is letting wistful iPhone users who downgraded to capped plans last summer to switch back to an unlimited data plan for $30. AP interviewed two New Yorkers who managed to switch back after calling AT&T's customer service.

This only applies to those who owned an AT&T iPhone before June 2010, when the carrier scrapped the unlimited data offer for new users. Officially, there are only two limited plans: a $15/month 200MB plan and a $25/month 2GB plan.

A couple weeks ago I also downgraded to a limited plan so I could tether my iPhone to my laptop. After using it for a day, I asked AT&T to switch me back to my unlimited data plan and the rep did so without hesitation. I had to give up the tethering option, however.

AT&T hasn't publicly commented on the so-called loophole, but a spokesman was quoted as saying the company handles customers and situations individually.

Meanwhile Verizon said it plans to offer a $30 unlimited data plan to new iPhone customers when it launches the phone on February 10. With strong competition looming, it looks as though AT&T's customers hold the bargaining power for now.

This morning AT&T also pledged to improve its offering for Android users.