Articles on Digg and Engagdet show that a new software called "ZiPhone" is released with which the the BL 4.6 iPhones can be unlocked in minutes ! The link to the Article above shows how easy it has become to unlock an iPhone.
All you need to do is download the ZiPhone software (ZiPhone 2.0 is the latest now) from www.zipone.org install the software. When you run it, tick the Unlock, Activate and Jailbreak boxes on the left pane and you're done.
Within a few minutes youe iPhone will be completely Unlocked!
Then just restart your iPhone and insert your SIM !