Saving on the thermostat

With the weather turning god awful this past week, discussions have arisen regarding itchy trigger fingers on the thermostat. Is it better to turn the thermostat down when you're doing home (or awake) or does that use too much energy to reheat the house? I always assumed that it should remain constant (though not a high constant).
Well here's an answer to that and more from The Straight Dope. It appears I had it all wrong.