arduino christmas light controller with light o rama

Hi, i am trying to get a light system up for christmas this year and had a great idea, what if i could use a 8 channle relay board with my lights. Then i was wondering is there a way to controll that over usb with the light o rama software. Then there was a problem, i have no udea how to interface my arduino with the light o rama software. I know that the software works with conntroller boxes other than the ones they sell but i dont know how to do it. If you could help me with ideas that would be great. P.s. i have a arduino with a atmega 328 and it is a duemilanove. It is not a clone or any thing. There will be acomputer that can be plugged into the arduino while it is doing the show so that is not a problem. Thanks for your help.

Give some links to the software (or site), some link to the hardware you want to use (apart from the Arduino) and you increase your chances to get an answer.