I'm oh so tempted to purchase a new MacBook, but I am trying to make the G4 Powerbook (1.25 GHZ) last longer. I feel like things have slowed down since my install of Leopard. I've got about 20GB of my 80GB hard drive left and I'm working on a big project in iMovie for my in-laws. I'd have to replace 2 512MB with 2 1GB. Will I notice much of a difference going from 1GB memory to 2GB...or at least a $180 worth of a difference?