Last year at Google IO 2011, Google announced Android@home, an open source Home Automation Framework. But it seems that it will take a lot of years until it is ready with all home appliances supporting the framework.
So if you dont wanna wait and explore some options with Home automation, there are quite some well know microcontrollers around, which can be programmed to automate your home using various sensors and motors to perform a desired task. One such open source Hardware which comes with integrated microcontroller on Board is “Ardunio”. There are various types of Ardunio boards out there. One out of which has been quite popular recently is Ardunio Uno which has Atmel ATmega328 microcontroller on board with input/output pins and flash memory which makes it easy to program using a simple computer, software, sensors and motors.