Its really nice if you have already bought the Harry Potter Books, in case you haven't and are planning to purchase them, I have this little request to make, PLEASE SWITCH TO AUDIO BOOKS!
Audio Books help in saving paper, besides they are really convenient. You can either listen them online or download them to your machine, your choice. You can carry your Harry Potter stories that way, anywhere, in your phones or iPOD. They are not bulky, and I swear, they're really very well narrated, you'll enjoy them a lot, I've had all of them. The UK version is read by Stephen Frying (that's the one I have) and the US version is read by Jim Dale. Believe me, it will be a nice experience and you'll save some paper as well!
So, I hope that you'll give it a thought and consider my suggestion.
You can conveniently Google for these audio books, they are available on the net.