Hi there, This will hopefully show you how to control electronics across the internet using your Raspberry Pi. It's not the best way to do it, and soon I will update this with a way to use MySQL to do the same thing.
This is not the best way of doing this, and I hope to update this soon with a MySQL solution.
Until then, I'd recommend keeping this to your local network (not over the internet yet).
However, there shouldn't be any issues, it's just a warning. :D
This will (at the moment) allow you to control your GPIO pins via a web interface.
The program running on your Raspberry Pi checks to see if a file exists, if it does - it turns the output on, otherwise it turns it off. All the web interface does (at the moment) is to either create or delete this file.