AT&T has published a fact sheet (http://www.att.com/Common/about_us/files/pdf/emerging_devices/iPad_fact_sheet.pdf )offering details on its iPad data service plan. As previously reported, the plan offers a recurring monthly charge with no long term contract.
For US$14.99 per month, you get 250GB; $29.99 gets you unlimited storage. Data plans for iPad include access to more than 20,000 AT&T Wi-Fi Hot Spots nationwide at no additional cost.
