Probably there are many appliances at home you would like to control using network interface. Panu has built a device called ArduPower which gives ability of controlling six power outlets via telnet. Basic server on Arduino requires a password in order to connect to it for obvious reasons. Once you access device you can do several things.
First of all you can assign a name to each outlet identifying the device connected to it. Then you can change status weather it is connected or not. Each outlet is switched using mechanical relay with status LED across coil. Outlet current state is stored in to EEPROM memory so it would retain state after power off. One feature we are missing here is scheduling. It would be great that device could turn on and off on specific time and date. With a bit Arduino coding it can be expanded to do more things and even add more sockets to control.
Embedds highly recommends EasyEDA for circuit and PCB design