This model from Honeywell is fully programmable. It features four independent time zones per day, which means you can set it to heat to a certain temperature when you wake up, shut off when you leave for work, turn on again before you come home, then lower the temperature while you sleep. Each day is programmed separately, so you can change the settings for the weekend, for example.

If the word "programmable" makes you nervous, don't worry-the menu-driven software is very easy and intuitive to use. Note that you will have to hardwire the device to your power supply and to your heating unit-this isn't hard to do, but make sure you read the instructions thoroughly before you start.--Josh Dettweiler