some of his screeshots may be off slightly (well, nobody's perfect) , and certain instructions may have been omitted :

(a) BSD Subsystem should be installed (available somewhere in Installer) in Iphone before using Geohot's unlock within the install package

(b) For me , after Geohot's method was executed , i did not get a message stating my phone has been unlocked, instead it took slightly more than 5 minutes and the phone rebooted WITH NO SIGNAL

(c) To fix no signal issue after phone is rebooted and unlocked, proceed to:

http://www.hackint0sh.org/forum/showthread.php?t=28695

And read my posts