I found a bit on Crowley and Halloween [from an anti-halloween site of course, some people

Followers of Crowley: Major-General J.F.C. (‘Boney’) Fuller was a devotee of the heroine addicted, sex pervert, black magician and so called High Priest of Satanism in Britain, Aleister Crowley (1875-1947). Crowley boasted of being "the wickedest man in the world" and openly despised Christ and the faith of his parents who were Plymouth Brethren. Fuller indicated that Samhain (Halloween) was an important ritual day to Crowley and his followers and it still is today.
from http://logosresourcepages.org/HalloweenBook/occult.htm
For those of you interested in the history of Halloween itself, here is a good site http://www.asiya.org/sabbats/samhain.html
Anyway, you know where I'm going, right? Wouldn't tonight be a lovely night for the real ceremony?