I'm buying my first Macbook tomorrow! I plan on getting the 2.0 version but want to upgrade the ram to 4gb. I've never done it on my own before but it looks like it could be cheaper. A few questions.... 1) If i want to upgrade to 4gb, do I buy 4gb or just an extra 2? (i.e. do I remove the ram thats already there or just add to it?) 2) Are there any specific specs I need? 3) Any recommendations? I was looking at this one on macmall: http://www.macmall.com/macmall/shop...d~1972~actionId~getSpecificReview.asp#reviews but it seems so cheap...is it relaly a good deal?