Lower your heating bills with an inaccurate digital thermostat. Pressing the 'up' button would always increase the displayed temperature, but randomly would not actually turn up the heat, so it would be reading a few degrees high. (Or low, in the case of AC.) You'll feel warmer simply because you turned up the heat, even if the temperature didn't actually change.
Of course it should turn up for real some of the time, say 50-75%, as the effect won't work if you know it's not going to actually get any warmer. Your average room temperature would still be lowered, which translates to a lower energy bill.
Even if it doesn't fool you, the other people in the house who keep turning it way up wouldn't have to know a thing.-- Bukkakinator, Oct 18 2008 You could have a thermostat in every room and set the odds for each centrally according to how gluttonous each user is. The effect is more hidden because each setting is averaged as a whole for the setting.-- Spacecoyote, Oct 18 2008 This has been done by a contractor. It is better to use a bimetallic strip thermostat so the user gets a satisfying 'Click!' so that they KNOW they are in control.-- gnomethang, Oct 18 2008 random, halfbakery