by NY Times writer David Pogue in his Pogue's Posts Blog
(excerpt - first few questions)
Anyway, here it is: the ultimate iPhone Frequently Asked Questions list, complete with answers.
ANSWERS TO ALL YOUR QUESTIONS:
Can it be used with anything but Cingular? –No.
Is it an “unlocked” phone, so I can use it with a carrier other than Cingular? –No.
Will there be a non-Cingular version? –Not within the first two years.
Can I put my T-Mobile SIM card in it instead of Cingular? –No.
But what if I keep asking? Then will it be available beyond Cingular? –No.