I have a 15" macbook pro. I like it because when I write papers, I will often have a page of notes and a page of writing side by side. (And when I'm procrastinating, I'll have netflix side by side with tumblr or gradcafe!) Also, SPSS and Excel can get really frustrating when your screen is small compared to your data set; when I know I'm going to have to use SPSS at work, I try to get there before the other undergrads so I can get the widescreen monitor . That said, I have bad shoulders, so I often wish I had gotten a smaller one when taking my laptop to class. I think GeoDude's idea of a small laptop for class and a large monitor you can hook it up to is really smart. The only problem I see is that it limits where you can work: I like to move around when I work, sometimes sitting at my kitchen table and sometimes sitting on my couch or wherever, and a fixed monitor would keep me fidgeting in one spot. But if you're the type of person who always always works at a desk, or you're willing to stay at a desk when you need a bigger screen, then that sounds like a good compromise.