Sleep: Gadgets giveth, gadgets taketh away

It's hard to imagine now, but 100 years ago people used to sleep at night. Nighttime was generally dark, quiet and boring. Must have been nice.

Then inventors, engineers and other troublemakers ruined everything by improving light bulbs and the provision of electricity. Radios didn't help, either.

Fast-forward to today. PCs and consumer electronics provide us with a gazillion things to do all night. Video games, TV, social networking, chatting with friends, catching up on work. These things are addictive, and they call to us. Getting a good night's sleep has become a challenge.

Poor sleep, or what they call " " (sleep compromised by constant waking), particularly affects younger people -- teens and twentysomethings -- who are developing the habit of rarely sleeping well.

Sleep problems hit travelers, too. Jetlag, unfamiliar hotel rooms and other unavoidable realities of travel can make it very hard to sleep.

The recession is making sleep more challenging as well. People are lying awake nights thinking about their 401(k)s, layoffs and other stressful financial realities.