In my opinion, Macbooks are overpriced toys. They look pretty and they are what the "cool kids" have right now, so they get a lot more press than they are due. They've stopped being computers so much as status symbols, and like any status symbol - be it designer jeans or sneakers - they are priced accordingly.
Additionally, I know 3 people who utterly shattered their Macbook Air - one of them the first week of having it. And for the privilege of owning a malnourished computer you are forced to sacrifice a lot of features, such as; only one USB port, no optical (CD/DVD) drive, a single mono-stereo jack, no Ethernet port (to get online you have to use wireless), a built-in non-replaceable battery, no upgradable components, etc.
All for just $3000!
Now, if you are a real college student on a real-world budget, and your parents can't drop you 3gs for the asking, go with a functional and fully equipped Dell/Gateway. Pay a little extra for their extended care service, and you should be all set! A friend of mine got a fantastic computer for less than $600 on sale at BestBuy. 4 years in and zero problems. Don't fall into the iTrap.