Sweet. Do you plan on making a carbon arc area light (like a spin off a NEMA head)? I'm definetly going to buy one of your fixtures when/if you ever make them. I'll have to read some more information on carbon arc fixtures though since i really know next to nothing about them. I don't even know what a carbon rod is!
Fascinating idea of using old technology in a modern fixture design. I'd guess there would be code-related and efficiency standards that a product like this wouldn't meet, but still, it's a cool concept. How many hours might you get get from a carbon-arc fixture before it needs servicing?