This just in! Last night my husband went to a press screening for Harry Potter and the Half-Blood Prince and came home to report some knitters' scoop!
Apparently, in the first act of the movie, Professor Dumbledore is visits Professor Slughorn. While there he asks to use the loo, emerging from the bathroom with a knitting magazine in hand. He asks Slughorn if he can keep it because he likes the patterns.
Ok, I know a version of this is in the book too, but it's nice to hear that D.'s love for knitting gets another screen shout-out.
You heard it here first! ;-)