There are two types of smart home systems; time- based and parameter-based that can ber used individually or combined. A time-based smart home is where a particular service would occur at a set point during the day, for example, in the hallway the lighting may be set to become active at 6pm or relaxing music could be set to play at a time when the homeowner returns from work.
If you are interested in setting up a time controlled system, check out the x10 mini-timer, which allows you to schedule the times for up to eight lights and it also consists of a very handy all on/off switch. You will of course need to have your lights etc plugged into x10 receivers.
A parameter- based smart home system can become active at any point but requires a trigger of some kind to set it off. The temperature of a home may alter depending on outside conditions, you might even consider your household alarm a parameter-based system because it typically works via motion sensors.
Please visit http://smarthomeguru.blogspot.com for more on smart homes.