Both this side bar and the recent New York Magazine article are worth checking out. If your time is limited just take a look the sidebar for the practical tips on helping your kids to get enough quality sleep. If you've got some time to read the feature article by Po Bronson you can get the gist of some recent research that shows some of the more severe effects of kids getting too little sleep. It turns out that not only problem behaviors can result from being under rested, but even significant cognitive declines that really add up.
Thanks to Heather Decker for passing this article along.