X10 Home Automation
 

I bought a bunch of the X10 wall modules years back, and got xTension software, which runs on mac platform. I don't do anything really fancy - I just use it to turn lights on and off and keep power demands down. I also have a setback thermostat on the house to reduce demand when we are away or asleep. Every bit helps!

this good way to save but how much is the X10 wall module?

There are a couple of pieces needed - the wall modules is basically like a smart switch - my computer turns it on and off through the powerline - the modules are a couple bucks each ... Its all local network stuff - and its not talking through the internet, so better security for my house.

Google is your friend - surely you can this up on your own?