Holy sh*t, they are already visiting?! Thanksgiving is more than a week away!
I agree with the other posters, go buy a new outfit, go to the movies, buy a new book and go hang out at a coffee shop for a few hours (buy some coffee). Go for a nice long walk around the city and enjoy the mild weather we're having.
I can honestly think of a million things to do to kill a few hours during the day that doesn't involve being at home.