In elementary school, my teachers would run out the clock on the school year by watching movies in class every day for the last week or two. Back to the Future was always one of them. The teacher never bothered with the pretense that it was part of some science lesson about the nature of time or anything like that. She just popped the tape in and tried to catch up on paperwork. Inevitably, though, the movie wou'd laugh at the pop-culture gags and bite her nails over the possibility that Michael J. Fox as Marty McFly might pre-empt his own existence by messing up his parents' high-school romance. Twenty-two years after the film's release, it's still a great family film and a poor babysitter. The wife and I rented it recently for our summer-bored kids so we could catch up on work. But laughing at the dated Huey Lewis soundtrack and Crispin Glover's bizarre portrayal of McFly's dad, we got about as much work done as my teachers did years ago. Back to the Future shows at midnight Friday and Saturday as part of the Midnight Madness series at the Landmark Inwood Theatre, 5458 W. Lovers Lane at Inwood. Visit landmarktheatres.com.