I know this thread is a little older but a really cute movie with a ferret in it is 'Along Came Polly' with Jennifer Aniston. Her ferret is blind, LOL. One of my ferrets is going blind and she does occasionally bump into things, not hard so it's kinda cute.
I'm also a sucker for 'Kindergarten Cop'. I wished the familiar in the 'Golden Compass' would have kept his ferret form for more of the movie.