I also wanted to have the video events turn the lights and appliances on and off using X-10 control. After quite a bit of research, the best solution I could find was to use the x-10 Firecracker
which is a dis-continued serial port (DB9) dongle that you can find on eBay for $5. Unfortunately, there was no built in Flash/Arduino interface for this device so I wrote my own which turned out to be fairly easy in Action Script 3.0 using the Timer class. This website
was great and has everything you need to know to interface the Firecracker.