It looks like the days (literally, just days) of having to pay almost $100 for an iPhone unlocking program are over...more or less. We don't recommend or suggest that you try any hack due to the possibility of damaging your product and, according to some reports, the risk of bodily harm. That said, it is certainly understandable why some people might want to give the iPhone a try. For those intrepid souls, please read on:
“Our friends at TUAW pointed out that the iPhone Dev Team has struck gold for everyone who wants an iPhone but not an AT&T contract. Yes, that's right: the team has released anySIM, a free, completely GUI app for unlocking your iPhone.
As of this writing, you can download the app from the iPhone Dev Team wiki (http://iphone.fiveforty.net/) and use a tool like the latest iFuntastic to install (version 3 of this app brought a file manager), or the team says anySIM should appear in Installer.app (a component of AppTapp, our favorite tool for dead-simple wireless iPhone app installation and management) pretty soon.”
Keep in mind that you get what you pay for, and that the hack doesn't seem to work on all iPhones. It'd be quite embarrassing to bring a broken iPhone back to AT&T and ask them to replace it because you tried to unlock it.
If you must try unlocking an iPhone, it might be best to hold off a while longer. There could certainly be software fixes that might allow a greater success rate in unlocking the iPhone.