Now don't get too excited...I am NOT saying you should encourage the kids to do that at school...it is just what the article hooks you with!
And realizing that everyone in my district has been using their laptops for a year now (gosh, time flies when you are having fun!), here is an article on how to clean a laptop keyboard. The ol' turn it over and shake isn't necessarily the best thing to when the keys are attached to the unit itself. :-)
Nice website overall...good tips on lots of stuff HowtoCleanStuff.net