Well, looks like I need a new laptop. I'm using an ibook G4 power PC. Can't do any upgrades on the apps I use now - I'm SO outdated. Thought about upgrading to leopard but I don't think it's worth paying 170.00 for not much of an upgrade.... What is the difference between the mac pro and mac air besides the weight and thinness? I don't haul my computer anywhere with me - I just use it at home.