I'm using a Powerbook G4 that I bought new in 2004. I wanted to get some suggestions on what I can do to upgrade. Powerbook G4 1.5ghz 17" 1gig ram OS: I've never upgraded, still running 10.3.9... What should I upgrade to? ... I'm guessing the newest OS out there won't run on a G4? I only want to spend a total of $500, maybe less. What else can I do to get this powerbook running better?