the only reason to put a cold cathode in a computer case is to be cool in some way. while you could manually flip a switch, it would be a lot cooler just to press a button in a menu and have the light turn on.
fairly soon, i should have kits for approximately 25 12V DC computer controlled switches. should be good up to 14 amp, which is more then a cold cathode would use...
I am currently working on getting the values for components correct.
the technical info:
Parallel port connects to an "optoisolator". this means if the cathodes or whatever do something bizzar, it won't send a spike back to the parallel port. the parallel port turns on a LED, and the light excites electrons on the phototransistor on the other side of the chip.
on the other end of the optoisolator is a N channel enhancment mode MOSFET. similar to the approximately 50 million in a modern CPU, just a bit bigger then 90nm.
in any case, it is likely there will be enough kits left over after IEEE members get them.
it is possible that a future project will be a similar switch, but for 120V AC like you would find in a house.
That would be sweet to be able to control them through a menu. I personally don't know enough about that area of computing to ever make it happen, so I have been forced to use switches, switches, and more switches.
I would definitely be interested in one as long as it doesn't kill anything.