While playing around with my PowerBook G4, I decided to mess around with G4 Fan Control and set the fans all the way up(by setting the max temp to 10c). After about 30 mins, the lowest my PowerBook went was 34c. Having the cold air going through the keyboard is nice though. I wasn't really running anything except for TFF(one tab, light page),Terminal,Finder and iStat. Just wondering how low your PowerPC can go? I uploaded a zip that includes G4 Fan Control(CMD, don't worry there's instructions!),iStat Menu.