I got an email from the AT&T this morning that started off well:
AT&T is now offering free AT&T Wi-Fi access to our iPhone™ customers. That means free AT&T Wi-Fi access at thousands of hotspots nationwide, including Starbucks®. Hotspots are available in cafes, bookstores, airports, hotels and universities nationwide.
Fast net access at no additional charge? Nice. All you have to do is follow these simple instructions:
Activate Wi-Fi from the settings icon on your iPhone.
Select "attwifi" from the list of available networks.
Enter your 10-digit mobile number and check the box to agree to the Acceptable Use Policy. Tap "continue."
You will receive a text message from AT&T with a secure link to the AT&T Wi-Fi hotspot. You will not be charged for the text message.
Open the text message and tap on the link for 24-hour access to the AT&T Wi-Fi hotspot.
I do see their point. Automatically recognizing iPhones by MAC address and having it just work would deny people the satisfaction that only comes from really laboring for something—like MMS messages.