Keifer Sutherland stared in an old movie called "Flatliners" where he played a medical student who, with 4 friends, killed himself medically (and deliberately), while they brought him back to life to find the answers to life after death.
I find this ironic since in 24, Jack Bauer has died twice and was borught back to life both times, and on the episode when Jack Bauer killed Paul Raines, Jack yelled, "He's flatlining!" which is in obvious reference to this film.
That may be true, but when my addicted mom was watching that episode on DVD (she's already watching season 5 reruns on Fridays), and she heard Jack Bauer say that, it instantly reminded her of that movie, and she said she could tell that Keifer was "promoting" the film.