What are the merits of having a pentium 4 over an intel celeron in a laptop. I need to get one to replace my crappy desktop, but really need a portable. I will be using it for microsoft office programs, photo editing and the internet. Can anyone help me on this? I have seen a Sony laptop which looks pretty good and was just wondering how much of a difference pentium makes if I am not playing fast games or doing musicy things on it.