This example provides code to control an optocoupler circuit. The example is built upon a remote wall socket controller. You can control the remote wall aocket with an android device by sending bytes to a console application on your desktop via sockets. The desktop application sends serial data to the hooked up Arduino by using the RXTX library for serial communication.

Make sure to include the RXTX library in your Java installation and follow the installation guide on their project page:
http://rxtx.qbang.org/

For details about the project please check out: http://marioboehmer.blogspot.com/