We meet every day in a computer classroom or in a wired classroom where you may bring your laptop and fire it up to check our homework page, and maybe even open a Maple worksheet to do something inspired by what bob is doing with his through the ceiling projector.
You will probably want to check email when you enter class. I understand. But there is a great temptation to abuse this opportunity and continue well into the class period, moving on to surfing or computer games or other distractions.
Class time is for discussion of homework problems you were assigned to be done by class, predigesting new material, and interaction. Needless distraction for you or your neighbors is a bad choice.
In computer classrooms there is an override power switch that kills power to all student computers. I have always been against such overkill responses to this problem. With your own laptops, there is no control other than requesting you to shut down. Please be reasonable about how you use these machines. If you come to class, please come to participate, not waste our time.