I've got a part time job on campus, and as such I've got an office with my 24-inch iMac in it (not to mention a 10,000 core supercomputer that I'm a sysadmin to). We've got plenty of linux labs (I used to admin those as well). I definitely could survive without my macbook pro. But at the same time, there's something nice about having my own private dev machine. A cheap machine on craigslist couldn't handle 5 hours of class without being plugged in. I couldn't build iPhone Apps in Xcode instead of paying attention in my CS classes. Also, I doubt a used laptop from craigslist could survive a trip through my windshield (happened last thanksgiving when my car rolled 4 times.) And an old machine is not going to have backlit keyboard, which is very useful for 12-4am coding sessions. At the same time, I'm pretty sure my wife (History Teaching major) would do fine on a used machine.