I have a 4 month old MBP 2.4 with 120 and 2Gb. I hear its best if you upgrade your ram. I run a lot of applications at once, like CS3 sketch up and auto Cad. Would 4GB of ram make it run better? How much would it cost. And what would be the best deal? And from where... what brand...is it hard to install yourself. Thanks guys!