I am fishing around for an iBook, and found one on eBay that seems to be a good deal. The guy is advertising an upgraded 5400 RPM 40Gig HDD in the iBook 800. I asked him if this was a self installed item, as I see all the HDD's in iBooks on apple.com are 4200 RPM. He never directly answered the question. I want to add Applecare to this if I get it, and I'm afraid a custom item will void that potential. Is this a reason to worry? Also, someone talk me into spending $$ on a new iBook (since noone seems to want to trade...see my post in For Sale/Trade).