We love to automate things in our home here at Lifehacker, and it turns out that with just a router, an Arduino and an RF switched outlet, you can control pretty much any electrical device you want from your smartphone or computer.
This tutorial is courtesy of Instructable user mrx23, who turned an OpenWRT-compatible router into its own little web server that sends serial commands to an Arduino, which then controls switched RF outlets via a remote control. You can access the switch with any browser and use it to turn on and off pretty much any electrical device you want — lights, music, video games systems or anything else lying around your house. Check out the video to see it in action, and hit the link for more detailed instructions on how to set it all up.
Home Automation Server with Router [Instructables]