It's not confirmed by the telecom giant, but several people have been able to replicate it: If you own an iPhone, you can log in at an AT&T hotspot or a Starbucks through their AT&T portal link (upper right corner of the T-Mobile screen, and soon to be a unique SSID), enter your phone number, and have free access. This is nifty, and not unexpected. AT&T is providing free service to 7 million DSL and fiber customers and 5 million remote business access customers. Adding a couple million iPhone users as an additional tie for continued loyalty is a no brainer.
Stories with pictures at MacRumors and Ars Technica. I'll test this out with my neighborhood Starbucks tomorrow. [Link via Fabio Zambelli]
Update: Well, that didn't last. It was clearly a test, only a test, and AT&T has pulled the plug for the moment. I suspected that with no announcements, and a national network, they might simply have flipped a switch not understanding how rabid we are all.
Seems to be working from the Starbucks here in San Bruno (which does already have the attwifi SSID alongside the tmobile one). When you connect using an iPhone, you get this login page now:
And you can login by entering your iPhone mobile number in the box. The page doesn't show up on other devices. It seems to be basing the decision of which login page to send on the user agent in the browser, but I haven't confirmed that yet (will try to do that later today).
[Editor's note: I was also able to get access at a Starbucks today in the Seattle University District. The baristas were openly contemptuous of T-Mobile--not sure why. But they will get free AT&T Wi-Fi access, one of the perqs of the AT&T deal.--gf]