Dev-Team was officially released the new version of pwnageTool (Torrent link) that support iPhone OS 3.0. As they said iPhone 3G users that use yellowsn0w to unlock their iPhone‘s should not use pwnageTool and have to wait until releases of Ultrasn0w.

This app is suitable for the recent 3.0 release.
PwnageTool will NOT work for the iPhone 3GS.
PwnageTool WILL work for Original iPhone (1st Generation), Original iPod touch (1st Generation) and the iPhone 3G.

Read more on Dev-Team Blog