Hi all. I'm thinking about switching to a Mac but I've got a couple of questions I'd like to clear up before taking the plunge. I'm starting a PhD in Cambridge next year and have decided to ditch my desktop and get a notebook. At the moment I have a really decent P4 desktop that mostly runs Linux (for work) but also some Windows. Apart from email, internet browsing, iTunes, and typing documents in LaTeX my main requirements from a computer are that it be able to run Matlab 7 and Mathematica 5.x. Since I'm going to the UK I don't want to bring my desktop with me. I'm interested in getting a 14" iBook or a 15" PowerBook but I'm a bit nervous about the following things: 1) The iBook seems a good bet but the 1024x768 resolution would *really* piss me off. Am I right in thinking that the video card in the new iBook will only run at 1024x768 even if plugged in to an external screen? 2) The 15" PowerBook looks really sweet. The screen in particular seems much better than that on the iBook, but I'm nervous about spending that much extra money when the current PowerBooks seem to be coming to the end of a product cycle. Is it worth waiting until November to find out what happens in Paris? 3) Speed. As I said earlier, I absolutely need to be able to run Matlab and Mathematica. How fast are the PowerBook and iBook when compared to the Pentium M? Apple seem to ask for an awful lot of money for a system that could be whipped by a similarly priced Intel notebook. 4) Apple's RAM prices are ludicrous. How easy is it to upgrade the RAM in the PB/iB after buying? My apologies if these questions have been asked before, but I'm really anxious not to waste money.