I tried an iPhone in Santa Fe NM via ATT and it simply does not work, TMobile has the GSM coverage here, and ATT is way, way flaky.

So I plan to get an iPhone within the next month (MacWorld!) and unlock it.

The issue is: Sim vs Software Unlock.

As I understand it, the software unlocks all depend on bugs in the Apple firmware. Each Apple upgrade fixes the bug, and there's a couple of months needed for the unlock software community to find a new work around.

The SIM unlocks are a bit harder to understand. For example, do they also exploit a bug to work? Or are they pretty foolproof? Apparently the SIM unlocks take jailbreaking. Does this depend on a firmware bug?

So basically the question is: do SIM unlocks promise a more secure unlock as the firmware upgrades progress? Or are they dependent on firmware flaws in the same way as the software unlocks?

Thanks,
-- Owen