AT&T hotspots are now offering free Wi-Fi access to iPhone users.

Barnes and Noble, Starbucks and presumably all of AT&T’s 71,000 hotspots are now offering iPhone users a custom portal to access free Wi-Fi. A special iPhone formatted page asks for your mobile phone number. Once entered, you can access the Wi-Fi access for free.

MacRumors has been able to confirm this finding at a local Barnes and Noble. Blurry photo provided:

AT&T recently partnered with Starbucks (displacing T-Mobile) to provide Wi-Fi access to Starbucks’ 7000 stores nationwide. This partnership allowed existing AT&T broadband customers free access and AT&T promised that it would “soon extend the benefits of Wi-Fi at Starbucks to its wireless customers”, but no official announcement has yet been made

Even better – this functionality is based on the iPhone’s user agent – which is easily imitated with the browser on your computer. This could be a nice bonus for musicians that have invested in Apple iPhones – and anybody that’s a bit of a geek.

We haven’t had a chance to give this a try yet. If you’re at one of AT&T’s 71,000 hotspots, give this a try and let us know how it works!