Good to know about your enthusiasm about the Christmas Lighting! Did you find anything yet? I was looking for similar products few weeks ago and found a few on Amazon. You can try using a programmable power strip from PwrUSB (pwrusb dot com)
You can hook up the power extension box to a computer via USB and program it anyway you like. It's okay, they provide a bundle easy to use software. So you don't actually need to know any computer language to flash the Christmas lights the way you want
If I am recalling right, you can program PwrUSB to flash the lights every 2 seconds on different power outlets. I was able to create some extraordinary animated lighting effects by putting diverging lighting on different power outlets (there are 4). Give it a try, you will love it!