You're a bit late to see the site in it's live form. Originally there was a webcam video feed down below, showing the roof of my house, and the buttons below it would allow you to change the pattern and the speed. I've posted a video below for future visitors to the site, to allow you to see what it was that you missed. Check it out, and plan to come back here again next year to see what I come up with next.
The above buttons were linked to a CGI script. That script took the mode and speed requests, and relayed them on my LAN to an "Arduino". More accurately, a "Nanode" which is slightly similar to an Arduino Ethernet, but uses a much different ethernet chip. And I swapped out the ATMega328 MCU chip for a Teensy++, which gives it oodles more flash, ram, and IO. (I'd love to see the Nanode get redesigned to use a Teensy++ by default)
I wrote a Christmas light controller sketch the year before, but it was for 8 strings, not 10 like I had this year (2011), and I managed to lose my final revisions somewhere along the way (DOH!), so I just re-wrote the whole thing from scratch. I learned a fair bit about programming the Arduino since then (my 2010 display was my very first Arduino project, and actually my whole reason for getting an Arduino). Speaking of last year's setup, you can view the whole build and all the details about it here.