Home automation is something that most people are dreaming of, while being a bit afraid of, because most of use think that having a fully automated house requires some maintenance and knowledge. There are, however, systems that are totally autonomous once they have been installed. Edward Cheung successfully built one of these system.

As he says on his home automation website,

Few of us can afford a butler. Fortunately electronics and technology can compensate for this by allowing us to remote control many devices in our home. However, home automation does not mean just being able to control your home's appliances from a distance, but also includes intelligence in the system to better serve our needs.

Thanks to his installation, he can control most of the electrical appliances of his house just from his watch ! He also automated most of the annoying tasks, from opening/closing the windows to irrigating his garden. He was also able to precisely estimate the cost of a shower by installing some sensors in his water system, his water heating system, and his electrical system. The amount of radioactive Radon was also quantified, and he was able to remove it thanks to a homemade geiger counter. As you can see, things can go pretty far once you're in it.

I can only recommend you to check his home automation website if you are interested in home automation. I am sure it will give you some ideas. Even if you do not end up with such a complex system, you could install some simplier, yet useful, home automation components.