10. X10 - Home Automation System

"X-10 modules are devices that plug into an electrical outlet and allow you to remotely control the power to a lamp or an appliance that is plugged into them. There are also X-10 modules that install in place of wall switches to control lights, and there's one that can be used to set back a thermostat."

These X10 folks make a really cool dongle called the Firecracker. These allow for the control of X10 devices via a serial-port of your PC. Programs like bottlerocket and gtk-x10 allow Linux programs to control X10 devices using the Firecracker device. You may be able to get the Firecracker, a remote control, a receiver, and a lamp module for as little as $5.95 U.S. (special promotion).

GNU Phantom.Home is a computer controlled home automation system. The software includes a circuit diagram for building the Phantom.Home.Controller, a simple circuit board that attaches to your PC's parallel port. Using the combination of hardware/software you can control (i.e. flip on or off) nearly any 120V device. And with a little bit of electronics know-how, you can probably control nearly any device at any voltage by modifying the circuit board to meet your needs. The simple circuit included can be created and built for around $25. The modules cost around $10 (basically a heavy duty relay).

Turn that light off when not in use!