It's the time of year where I'm constantly switching between air conditioning and opening some doors. A tiny switch on the side of the thermostat toggles the air conditioner, but it's so small I need to be right next to it to see which position it's in.
I propose a lighted thermostat. It has plenty
of clear plastic trim on it already, so simply add some LEDs to indicate what it's doing. It will glow blue for air conditioning mode, red for heating mode, and yellow or green for untreated air circulation. When the respective appliance is actually running, the light will fade in and out.
This way I can see from a glance what it's doing, and act accordingly.