I have a friend who often survives on four or five hours of sleep a night. He's proud of that, as though it's a measure of his manhood.

   Listening to him, you'd think sleep is optional, like flossing your teeth or wearing underwear. The only time you should sleep is when there's nothing good on television. Or when the president is addressing the nation.

   Compared to my friend, people like me who need seven or eight hours of sleep are definite slackers. We're sleeping our lives away. We might as well be on drugs.

   Unfortunately, too many people in America are like my friend, cutting back on sleep and walking around like zombies.

   And some of these zombies have jobs that require a lot of energy and concentration, like operating heavy machinery, directing air traffic and keeping track of presidential scandals.

   They drink several pots of coffee a day, just to keep from falling over. And if they do fall over, they blame it on a lack of caffeine.

   Some experts say Americans are sleeping as much as an hour and a half less per night than at the turn of the century. It's no wonder people today often drive through red lights, get married to the wrong people or forget to pull their jeans over their underwear.

   Of course, the consequences of sleep deprivation can be far worse than this.

   In a 1993 experiment at the University of Chicago, rats that were kept awake for two and a half weeks dropped dead. This is apparently one of the most effective ways of killing rats. If you have rats in your home, you can kill them by blaring rock music day and night. And as a bonus, some of the neighbors' noisy pets might drop dead, too.

   Humans are a little more resistant to rock music, thanks to groups like Metallica and Kiss. But the effects of sleep deprivation can be just as harmful. A sleepy driver can cause as much havoc on the road as a drunken one. A 10-second nap can easily turn into a permanent snooze.

   If you find yourself falling asleep while driving, here's some advice that could save your life: roll down the window, stick your head out and roll the window back up tightly. You weren't using your head before, anyway.

   Some people think it's a sign of strength to do without sleep, but it's really only a sign of stupidity. Like drunken driving.

   Unfortunately, our 24-hour society encourages people to skip sleep. If there's no work to be done, there's fun to be had. Many stores and restaurants are open all night. Why go to sleep when you can go shopping?

   With cable TV and the Internet, there's plenty to do that's more exciting than sleeping: First, you watch a movie on HBO, such as "Sleepless in Seattle." Then you enter a chat room and start a romance with someone in China.

   At about 4 a.m., you fall asleep at your computer. Later that morning, at your office, you brag to a workmate that you've trained your body to survive on three hours of sleep. "I'm evolving faster than other humans," you say.

   Just before noon, your workmate finds you fast asleep, flopped over the coffee machine, your hair smoking.

   "Hey, wake up!" he yells. "You've evolved into a cigar."