OK, maybe "need" isn't such a good word. However, I'm finding more and more that I need quick access to web-based data wherever I go. I need to record quick thoughts and, as I'm writing more and more, I want something that I can toss in a bag or even some particularly baggy cargo pants. My BlackBerry can get me online and my MacBook is fairly light, but what I really need for both my day job and my writing jobs (ZDNet and a couple of books that are starting to take shape) is a computer that I can have with me all the time.
The obvious choice here, of course, is a netbook. I have an evaluation unit coming from Acer as part of their educational seed program for their Aspire One computers (and have used them briefly at trade shows); my initial impression is that, for my relatively small hands, the keyboard would be adequate. Dell's and HP's entries into the netbook realm also have very usable keyboards. The seed program from Acer is well worth checking out, by the way. Not only can you purchase the evaluation unit for half price at the end of the 30-day evaluation, but your school is automatically entered to win a full computer lab.
My problem, however, has always been my need for a computer with more serious horsepower than the average netbook can muster. Netbooks really are meant for web access, word processing, and other basic productivity tasks. Video editing? Not so much. Thus, I bought a MacBook and still lust after the new MacBook Pro. Even these machines, though quite capable of video editing (especially the latter), programming, virtualization, running math software, etc., just aren't portable enough to meet my daily needs.
Of course, for the price of a MacBook Pro, I can build a really slick desktop machine that can handle video editing, be a home server, encode all of my DVDs, music, etc. I can also buy a netbook or two. Sure, they won't be running OS X, but video editing in Linux has come a long ways and I have all of my needs satisfied.
Obviously, if you're a video producer and need to edit on location, a loaded MacBook Pro is the machine for you. However, for a writer/techie/geek/video hobbyist like me, as readers have already pointed out, it's hard to justify that MBP in a recession.
The same certainly goes in schools. Go ahead and have a dedicated lab of machines for multimedia applications or more sophisticated number-crunching. But in the mainstream classrooms, use those netbooks and thin clients. You'll save money and still give your users just what they need.