Tell your friend it might not be such a wise idea to put a fan so close to his HD... I dont know if they have changed over the years but fans used to have magnets in them and magnets+magnetic media=lost data... I do like the idea though and I could be wronge about the whole magnet thing but I would check up on it lol
magnets+magnetic media=lost data
he rigged the fan to run off the HD spindle