The iPhone has a removable SIM card
Remember how Walt Mossberg claimed that the iPhone does "not support SIM cards"? I even spent an entire post on this subject. It turns out that Walt was wrong. CNN:
Contrary to earlier reports, the SIM card is removable via a small drawer on the top of the iPhone.Maybe Walt's quote meant that it cannot use T-Mobile's cards? Which is true, as the iPhone is SIM locked to AT&T in the states.