I am wondering how to do this myself. I have a website that is hosted with "Hostgator" and I would like to use it to switch on or off a light, nothing to tricky. I even have the Arduino live at http://18.104.22.168:89
so it's port forwarded, and I have the example Sketch working.
How do I write a simple sketch that works with my website rather than Twitter to interface with my Arduino? Is it RSS?
I have a Micro SD card plugged in to the Ethernet shield, is there a way to store HTML, XML and PHP documents on it and just call them when they are needed?
Thanks for your help and time.