It could be 'Silver Streak' starring Gene Wilder and Richard Prior - the majority of the action takes place on a cross-country express train. Look out for Richard Kiel playing the 'Jaws' character known here as Reace, who re-appeared in the James Bond film 'The Spy Who Loved Me' the year after.
No contest. It's His Girl Friday (1940), a remake of The Front Page, starring Cary Grant and Rosalind Russell. Perfection. Click here: http://us.imdb.com/Plot?0032599
Gotta be a Star Trek movie.
They may not travel at warp speed the whole time but averaged out over the two hours it would still be faster than anything else.