I was on the Maritime Geocaching site and they give out annual awards for the caches and the people. We could come up with some Hallowe'en based awards such as "Best Night Time" cache, "best caching costume" (worn during the regular season - would have to go through pictures for that one!), etc. We'd have to have a couple of nominations and categories before the event and let one person, who is good at keeping secrets, do the voting.
At this point, I don't know if I can make it or not.