iPhone software-only SIM unlocking hack is finally available

So after quite a few delays resulting in many doubting the authenticity of the hack which resulted in numerous videos to prove that it was for real, the software-only unlocking hack from iPhoneSIMFree is finally available for individual iPhone users via four online retailers across the globe.
The launch was preceded by an exclusive video by Ryan Block of Engadget to demonstrate the unlock process from the start to the finish to further confirm the authenticity of the software-only unlocking method. Read all about it after the jump.

iPhoneSIMFree's software-only unlocking hack is finally available through four online retailers around the globe; they are Wireless Imports in the US, iPhone Worldwide Unlock in Australia, 1 digital phone in Germany (have temporarily suspending preorders), and iPhone 4 arab  in Saudi Arabia.
As of now based on information available the US online retailer is selling individual unlocks for $99 while the Aussie retailer was offering the unlock for half the cost at $50. The retailers are claiming to have received a very good response already.
The unlock might be a good option for those who are in countries where the iPhone is not expected to be launched until sometime next year but for others like US here are some points you might want to think about:

• Unlocking the iPhone may result in losing the warranty.
• So far we know that the only feature that will not work with the unlocked iPhone will be the Visual voicemail feature.
• There is no guarantee  that you iPhone will remain unlocked with the next firmware update. If an update is required, they will offer it for free IF they are able to provide it in the first place.

So if you don't care about any of these concerns then go right ahead and order the unlocking software or maybe even try out your luck with Engadget's SIM unlock give-away.
On a side note, as expected we also had the iPhone hacking community confirming that they will not be reverse engineering the unlocking solution.
In case you would like to watch the SIM unlocking process from start to finish download the video in wide VGA from these links courtesy Engadget (MP4 format or AVI format)
Update: Gizmodo was reporting some problem with the unlock but iPhoneSIMFree were quick to react in providing a fix for the problem, click here to read about how the unlock is working for others.

Update (30th September):
Instructions on how to Unbrick iPhone - Downgrade from iPhone 1.1.1 to iPhone 1.0.2 for the Hacked iPhone

Update (27th September):
It is advisable not to try this for now, read Breaking News: iPhone Firmware Update 1.1.1 unlocks iTunes Wi-Fi Music Store BUT seems to Partially Brick Unlocked iPhone for more details.