Great news!

Now the community can unlock locked down iPhones that either;

A) Got updated when the whole slew of 3.*.* updates came out, or

B) Purchased an iPhone with either of the updated baseband version

You're now in luck!

According to the Dev Team, geohot was able to turn a public crash into an injection vector which can then be used to unlock the phone (called blacksn0w), he's made this public via cydia by adding the following repo to Cydia (via the manage > sources screen):

http://blackra1n.com

After which you'll need to search for blacksn0w and then run it.

Good luck and keep that phone unlocked!