Believe me, having total control of things at home is much better than letting them go by default. Say heater – usually we set it to some temperature and it does its job automatically. So following project pushes heat control to new limits.
Arduino based thermostat with web interface is simple thermostat that turns heater on and off at predefined threshold. But fun begins with web module which allows publishing data to web-page at regular intervals. It uses a pachube service where you can control things also. So there is ability to set temperature values from web interface. If you know that today you won’t be getting home, so why not to turn heater down a bit to save energy. This even can be done with any cell phone having web browser.