Hi Jenn,
I have lifted lines directly from the show, but I am careful to state at the beginning of the story that I have done so and attribute them to the writers of such and such an episode. I think that probably covers you legally, as long as people know that you aren't trying to claim them as your own. At least I hope so, because I wouldn't want anyone to think that I was trying to steal another writer's work.
Nan
