The iPhone Dev-Team has released an updated version of PwnageTool (4.1.3), which allows iPhone 3G/3GS users to safely update their baseband to 06.15.00. This is important, as earlier basebands (05.14.xx and 05.15.xx) are currently not “unlockable” using ultrasn0w. Baseband 06.15.00, however, is is compatible with ultrasn0w.
If all of this is a mystery to you, then worry not: Redmond Pie has published a guide on updating your iPhone’s baseband using PwnageTool. Furthermore, a guide for Windows users (who must use redsn0w), is also available. Mac OS X users can also take advantage of redsn0w.
As always, jailbreak and unlock your iPhone at your own risk. For more information, check out Redmond Pie’s guides (PwnageTool and redsn0w), and follow the instructions carefully! Download links for both jailbreak tools are available from the Dev-Team’s blog.