Unlike the new iMac, Apple's new PowerMac doesn't have a redesigned enclosure. But it does have a pair of G4 chips that break the gigahertz barrier for the first time, a psychological hurdle that is making Mac fans drool. Unveiled on Monday, the PowerMac features G4 PowerPC chips that run at 1 GHz. Apple also introduced lower-end models with chips that run at 800Mhz and 933MHzClick here for rest of article