From Dev Team Blog:
QUOTE
We have been working hard on a few other things. The main one being the 3G unlock codenamed “yellowsn0w”. This is now completed and is currently being packaged into a user-friendly application with the simplicity that you see in QuickPwn or BootNeuter.
The target release date for the unlock is New Year’s Eve 2008.
This unlock method is available to iPhone 3Gs that have 2.11.07 baseband or earlier, we did warn you.
You can tell what version baseband you have by going to Settings->General->About->Modem Firmware
The unlock requires a jailbroken 3G iPhone. It’ll be installable via Cydia and so it doesn’t matter if you have a Mac or PC.
Please refrain from updating your baseband, regardless of what version you’re at. We’ll have complete directions on New Year’s Eve.
We’ll stream a live demo of the unlock before Christmas (see the update at the end of this post)
The target release date for the unlock is New Year’s Eve 2008.
This unlock method is available to iPhone 3Gs that have 2.11.07 baseband or earlier, we did warn you.
You can tell what version baseband you have by going to Settings->General->About->Modem Firmware
The unlock requires a jailbroken 3G iPhone. It’ll be installable via Cydia and so it doesn’t matter if you have a Mac or PC.
Please refrain from updating your baseband, regardless of what version you’re at. We’ll have complete directions on New Year’s Eve.
We’ll stream a live demo of the unlock before Christmas (see the update at the end of this post)
The unlock that the Dev Team has promised to bring is finally going to be here on New Year's eve, codenamed yellowsn0w. Video demonstration is available here.
Say what? I didn't polish PC_EFI 
