iBook!
I have to agree! iBook.
iBooks are bulletproof. Powerbooks dent. A 14 year old can toss an ibook into a backback, then toss the backpack around, bump it in and out of lockers, drop it onto the floor even, and not fear that his iBook will be dented out of shape.
NOT mind you, that I recommend anyone deliberately bump around their laptop. But an ibook will take the punishment of being knocked about. Powerbooks really need more delicate handling.
Also--though this might have changed with the new powerbooks--historically, iBooks have had better battery life. That means he can go from class to class without needing to plug it in. Powerbooks haven't had very good battery life and can only last one or two classes before needed to be re-charged.
AND, iBooks have also tended to have better wi-fi reception--and I think there's less chance of it being stolen. A 12" powerbook, small and silver as it is, is a tempting target for playground thieves.
One question, billsafire: does your Dad know he can get a 14" iBook with superdrive for $100 less than a 12" powerbook with superdrive?
12" Powerbook with superdrive is about $1800
14" iBook with superdrive is $1700 ($1500 + $200 superdrive)
But I have to agree, again, with MacboyX--I don't know what you're going to be using this laptop for, but unless you're going to be taking classes where you NEED to burn DVD's--or if you're deeply into making and burning your own movies, why bother? Go for the cheaper iBook, and with the money you save buying an iBook rather than a powerbook ($300!) get extra RAM and Airport Extreme. Better yet, as MacboyX suggests, get a 12" iBook, and save enough mony to also buy a new iPod--maybe a new Mini?
You can always get an external DVD burner later if you want it.