Over on Ottawa Valley Airsoft we have our own event system set up.
It allows our local hosts to have self sign ups. You can see one of our latest games at http://www.ottawavalleyairsoft.ca/fo...read-1253.html
Its a great system and was designed and built by one of our local players from scratch.
I am not sure how the logistics would work for such a large site as ASC but it works great for OVA.