I gather that Hogwarts continues to use candles and lamps because electricity won’t work properly there. But is there a reason why they use quills and parchment instead of modern pens and paper? I can’t think of any reason why pens wouldn’t work just fine, and paper has got to be cheaper than actual parchment. And it can’t just be conservatism because the magical world freely adopts any muggle innovations that suit them. For the exchange rate of a couple of knuts, you could buy a pack of ballpoint pens that would cut by two-thirds how long it takes to write out an essay.
Because the Product Placement deal from Flair Felt Tip Pens ™ fell through. 
I’m going to say it’s because parchment and quills are Nifty.
I’m betting there isn’t a logical reason. It just sounds and looks better in a school devoted to arcane magic.
Thought it was because they dont get typical human inventions and what theyre used for, like a biro and a copybook for example…
Remember Mr. Weasley and the rubber duck? or the fellytone?
I would think that it has to do with the laws regarding the modification of “Muggle Artifacts.” Echanting pens would be against wizarding law, while doing the same to quills is not, as Muggles are FAR less likely to use quills in this day and age. It is easier to enchant Quick Quotes Quills and use Anti-Cheating Spells than it is to cut through the red tape of enchanting Muggle pens that could easily be misplaced and used by unsuspecting Muggles ignorant of the wizarding world. While quills, too, could be misplaced, chances are low that any Muggle would think to use it as anything more than an artifiact, and would not attempt to use it. Any exceptions to this logic would probably be rare, and easily taken care of by memory charms, which are more easily used sparingly than en masse, which would be necessary if the wizarding world were to use pens.
Because of the availiability of magic, and the fact that wizards are few and insular, the wizarding community has fallen far behind in the area of technology.
They don’t have pens because they never invented or imported them, and an enhcnted quill wroks just as well, anyway.
Besides, I’m sure that good penmanship is important to impress when it means that a diagram drawn in chalk on the floor creates a birthday cake instead of summoning one of the great old ones.
One word…
TRADITION
I think that BuckleberryFerry does an outstanding job of inventing reasons for the quills, but I also suspect that Ms. Rowling is simply not as thoroughly grounded in Speculative Fiction as to care. (Recall that the Chamber of Secrets is entered through an entrance built into a (late 19th century technology) faucet system in a(n early 20th century technology) lavatory, even though the chamber is supposedly hundreds of years old.)
Yes the entrance to the chamber of secrets is hidden inside a faucet, but then we learn in the first book that things in Hogwart’s often change around. Presumably the entrance was not originally through a faucet.
I think GMR and Cardinal gave the most accurate responses. They’re nifty and it fits with the motif.
I was thinking about this last night (insomnia!), but the rest of you have beat me to all my ideas. Ah well. I’ll just say that I think the real reason (i.e. the reason why Rowling actually wrote it this way) is just for atmosphere. These kids go to school in a big magical castle, they can’t be writing with cheap Bics! But if there is ever to be an explanation from within the story world, it probably will be because, as BuckleberryFerry said, at Hogwarts writing supplies are frequently enchanted and they want to avoid the problems of enchanting Muggle devices.
Hey, let me tell you… If I ever found a School of Wizardry and Witchcraft, my students are darn well going to be using quills and parchment. I mean, have you no sense of style?
Of course, what none of you’uns realize is that Rowling is secretly a lurker on this board, and she’s going to explain this one in book 6
I’m happy to learn that. This gives me an opportunity to remind her to explain how James Potter could have gotten to be Head Boy (c.f. Harry Potter and the Sorcerr’s Stone – The Keeper of the Keys) without having served as a prefect.
No doubt we’ll be hearing about that in vol. 6, Harry Potter And The Ballpoint Of Doom…
Or vol. 7, Harry Potter and the Hopelessly Anal-Retentive Muggle Bastards, subtitled Here, I hope you choke on it and now leave me the hell alone with all my money.
What I don’t get is this:
What’s an example of this? I don’t remember anyone other than the Weasleys, because their dad is fascinated by them, using a muggle invention.
The Weasleys borrowed cars from the ministry. There are elevators within the ministry building in the most recent book.
I think quills are used as proof that the user is magical. Anybody who has used a quill knows that it’s bloody difficult to write more than a line.
Amen, Devil’s Grandmother! I think that ALL quills in the wizarding world must be enchanted to some degree, or kids wouldn’t be able to use them. For that matter, many adults would have a hard time…