NOTE: It has been brought to my attention that the first site I linked to contains advertisements which some people may deem objectionable. An alternate link can be found below:
Incredible Christmas Lights!
Quick - someone get Andy! This must be duplicated! :)
Update 12-2-05: I found some more information on Carson Williams, the guy behind this stuff.
First, he's on Wikipedia (and honestly, what isn't these days?)
Also, here's another one of his light shows. The song isn't as cool as the first one, but it's still impressive.
There's a WGMD radio interview where he explains some of what he did. The host is kind of annoying, but there are some nice tidbits. Apparently the Trans-Siberian Orchestra (who did the music in the first video) really like the display and may be putting a higher-res version up on their own website.
Finally, he gave some text instructions on how it's done, and posted the sequencing file he used.