powerbook has a VERY quiet keyboard. Quietest keyboard I have ever used, even for a laptop. They use very thin key based on a rubber mount. You cant hear someone typing 5' away even in a quiet library. Also the keys are illumated and have brightness controls. Instead of painted letters on each key, its a clear plastic knock out which is backlit making typing in dark spaces very easy. The superdrive is very quiet and so is the HD. Nothing on a powerbook is noisy at all. The built in mic is also very nice for dictation and ichat. You can also just plug in an isight and record classes if you need at a very nice resolution. The isight also is powered by firewire and no bigger then pepper shaker and comes in a durable hard plastic case. The contruction is very durable too. Rounded corners and all aluminum contruction. No plastic is exposed and the LCD mount is very durable unlike some notebooks. Some other nice features that college kids would like is ichat, itunes, ipods, and something probably not brought up that often is easy networking. With easy to use AFP, SMB and FTP setups, its very easy to connect to school networks and share data with other people on windows, Mac, or Linux. Mac latops also make nice multimedia PCs. I often use mine as a DVD player and just connect it to my TV via a $5 headphone to RCA adapter and S-video. With airtunes, you can easily make any network a wireless one.
Not that PC laptops dont have features like this (some things are mac only), its just all in one easy package with a mac and very easy to hook up and use. Even for someoen who is tech saavy, its just nice to have things work without alot of effort. Hence why my IT staff mainly uses powerbooks. Its not that they have more hardware or software available, they dont, they just provide what most people need on a day to day basis in a very friendly manner.
Best thing about it for school is probably the price. With educational discounts its very competitive with other laptops.