Control your home theater from anywhere in the world
Here's a pretty cool project going on, completely open source with all the information available to help. The idea is simple enough, use an IR to Ethernet module to connect to your AV Devices from across the internet.
His project, called Ether IR, is an Internet-enabled IR repeater. It consists of an Ethernet-connected module with an IR LED mounted on it, capable of controlling your AV equipment. The board is hooked up to your LAN, and relays commands to your home theater via a simple web page. The equipment can then be controlled from any Internet-connected device, such as a mobile phone or tablet PC.