The iPhone Dev Team has officially released their 3G unlock, named yellowsn0w, to the Cydia app installer, which if not already available, should be available for download as soon as they get their repository in order, since it is New Years Day.

They also explained the message from earlier today. Interestingly, the unlock is not only able to unlock the latest firmware build, but requires it to work.

From their Blog:
“Now to explain the above screenshot. The soft unlock has undergone many changes in the last two days. The most significant one: the soft unlock will now be only for baseband 02.28.00 (the most recent baseband). Yes we’ve been advising everyone to avoid updating their basebands, and in general that will always be the best policy. Not every baseband version is guaranteed to have a hole through which we can inject the unlock.”

Make sure to read the Cydia site completely before trying the unlock. There’s been a few glitches and you’ll need to pay careful attention to the unlock procedure.