Bottom line, it all depends on one's needs.
Yes it does, and nothing mentioned by the OP is something that the OP's sister needs a PPC mac for
and I suppose, to clarify, I meant that PPC was being obsoleted by apps not supporting it anymore, partly due to the OS (eventually Apple will drop PPC support), partly due to the arch (sometimes too much of a PITA, as seen with apps like Joost).
Get one directly from Apple either through Edu discount or refurbished discount. Pick up warranty a month before it expires if she still has it.
ADC student discount is nice for pricier machines (e.g. MBP and Mac Pro).
Being in a college dorm, she'll hopefully learn how to share music & files over servers wirelessly. At the very least 1GB of RAM (NOTHING LESS!), Superdrive (DVD burner), and a mini-portable hard drive.
No, I wouldn't agree. If the Superdrive costs extra, it might as well be spent on an external DVD burner if she needs to burn DVDs. More useful, faster (internal 16x dvd burners are $30-40, so either external burner or external enclosure for the internal drive will be under $100), cheaper. The odds she'll need to burn a DVD on the go is very slim.
I'd bet that what would be more useful would be a flash drive or iPod, not an external hdd. The iPod doubles as a media player, the usb flash drive fits on a keychain. I got a 4gb flash drive for dirt cheap a month ago, it fits nicely on my keychain and I love it. I got U3 and PortableApps on it, as well as portable versions of some Mac software, so I can use all my usual apps without needing to install (and of course, it's impossible to install anything in a school lab ...).
and as for a spare battery, most people arent away from a power source more than 5 hours a day, which is the battery life of the current macbook.. soo.. why are you telling someone whos trying to save money that they have to buy all these different things when they dont need them?
I would disagree. I use my MacBook for almost all my classes (even math, har), and sometimes my battery can't go more than 2-3 hours at most. Five hours is if you turn off everything and have brightness at low and use TextEdit to take notes with a fully charged battery, not using Visual Studio in Windows in Parallels (dumb CS classes...), or using Airport with SubEthaEdit or Google Docs for collaborative notetaking at the same time I'm using Eclipse to play around with sample code and using Safari to research stuff online.
I had some Apple discount codes to burn, so I got myself an extra charger and battery a couple months after getting my MacBook. Even if I only use each battery for 3 hours at most, it lasts long enough to generally cover all my classes and gives me some time between classes to use for one day. A battery is significantly thinner than the charger, even without the extension cable. This also lets me choose better seats in class and gives me more mobility to move around, instead of sitting near the back where there's a plug or having to think about moving the power cord out of the way or in some position so someone won't trip over it.
I also have a Core Duo Mac mini, and while the speed difference between the two is definitely noticeable, it isn't nearly as vast as some make it out to be.
Depends on what you're doing
I think the bigger point people are making in this thread is that the Intel mac isn't going to be easily outdated like the PPC ones already have been, and particularly the cost of some of the PPC laptops is ridiculous considering the OP's sister has yet to have a need for something that requires such a Mac (like you with Classic). Plus whatever apparently slight performance benefit there is from using an Intel mac will only grow as time goes on.
The only major non-Universal app the OP's sister might need is Microsoft Office, and even that is going to see a Universal update later this year. Even if she doesn't get Office 2008, 2004 still runs okay with Rosetta.