This process is made really simple using the Teleduino sketch for your ethernet enabled Arduino. Haven't heard of Teleduino? That's cool, you may want to take a look at Arduino Control via a Web Service with Teleduino to get yourself started. It's designed to be quick and easy for rapid development.
This tutorial will guide you through the process of attaching a servo to your Arduino, and provide some example Teleduino API call to:
- Define a servo instance
- Set the position of a servo