Yesterday's report of specialty coffee chain Starbucks offering free-of-charge Wi-Fi access to customers has been made official, the company confirms through its sign-up page posted today. The deal offers two hours of uninterrupted access each day to Starbucks Card owners who use or top up their cards at least once a month, encouraging them to make regular visits to Starbucks that the company hopes will translate to increased coffee sales.

In addition to active use of the membership card, interested parties will also have to allow AT&T to send them four promotional e-mails per year. Customers with any 802.11.b/g capable device with web access can take advantage of the free Wi-Fi starting today.

AT&T has yet to confirm its plans to bring unlimited free Wi-Fi to iPhones and all Wi-Fi capable devices available through its cellular business, though these plans are expected to become public in the near term and already include the company's PC cards and USB modems.