UPDATE: Uploaded a new version with a temporary fix for if not working properly on the latest OTA?
ONLY flash the bootloader (HBOOT) aka "S-OFF" if you understand what it is, what it does, what it can do and how it can brick your phone if flashing it fails.
I can not be held responsible if your phone bricks, makes nukes drop from the sky and/or makes your wife pregnant.
Assuming you have the Android SDK (adb) in working order, some basic knowledge of how to use it and experience using the console for those cases something does go tits up.
Requirements: Android Terminal Emulator (from market), the archive attached to this post and a way to extract it to your SD card (file manager, PC, etc).
VISIONairy+ r12 (or higher) is as of v0.5 ONLY needed for rooting your phone, if you already have root you can skip this!
Download and extract the archive to the root of your SD card and read the included instructions (RTFM.txt).
If the first and second MD5 sums match, HBOOT is flashed correctly.
If the first and third MD5 sums match, HBOOT is not flashed at all and your phone still works like nothing happened.
If the first does not match second or third, something went wrong and you should NOT reboot your phone but seek help on the forums here!
In the last case, you could first try the hboot script again if that doesn't work something went awfully wrong and you should report back here ASAP but whatever you do ... DO NOT TURN OFF YOUR PHONE
Credits goto all who made this possible: Scotty, tmzt (eMMC write), Paul (MoDaCo) (VISIONairy+ root) and adwinp (first working S-OFF post).
(If I left some person out of it just sent me a message and I will correct it)