Wow. Hat's off to this guy for taking something sitting right under our noses and using it for a task that few would use it for, yet it is a near-perfect choice.
Basically, for those of you not familiar with pro lighting terminology, DMX is a form of communication between the lightboard and so-called dimmers which are basically fancy outlets to plug spotlights into.
So, Dan wants to do home automation. Specifically, lighting. X10 is slow and newish, and not that reliable. What does he do? He gets a serial to DMX interface, a couple of dimmers, and runs all his lights through that. It's a really impressive setup, because not only can things be automated, but they can also be controlled by wall dimmers. And the whole thing is run over CAT5 (aka regular Ethernet) cabling, which leaves him a ton of extra wires for other stuff, like his temperature sensors.
The unique thing here is not that he's automated his lights. Its that he's done it with an obvious, yet unconventional method. It's somewhat like my stereo: using a soundboard as your stereo is unconventional, yent nice to work with.