The Dev-Team is scrambling to come up with a quick patch to re-enable the Pwnage Tool for the iPhone. The newest Mac OSX update 10.5.6 disabled the ability to Jailbreak, or unlock ,your iPhone/ iPod touch.
While in in DFU mode (device firmware mode) jailbreaking applications can circumvent iTunes and hack the devices. There is speculation that Apple intentionally disabled the ability to boot an iPhone into DFU mode. TUAW spoke with the iPhone Dev-Team and they believe this isn't the case and that DFU disabling was unintentional.
There is a work around that involves moving the affected kernal extensions from 10.5.5 to 10.5.6, but the Dev-Team cautions that you do so at your own risk.
Links:
[1] http://www.maclife.com/user/yasobich3
[2] http://www.maclife.com/article/news/apple_owns_pwnage
[3] http://www.tuaw.com/2008/12/16/iphone-3g-now-unlocked-dev-team-speaks-about-dfu-problems/
[4] http://blog.iphone-dev.org/post/65126957/tis-the-season-to-be-jolly