I certainly don't remember any trick or treating when I was growing up, it just wasn't celebrated although I believe the Americans appropriated it from days of old England. We were in America at Halloween one year, it's such a big thing over there. I remember we were in shopping mall and young children were getting goodies from some of the shops, it was all pretty organised. My kids were young at the time and went quite slack jawed when they saw how much these American youngsters were amassing.
I do remember my brother and I, and various friends, making a "guy" and wheeling that around in an old pushchair and accosting strangers with "penny for the guy" thing which of course was begging. I don't think at the time I was aware of the historical significance of the 5th November, pretty horrible really particularly as we were Catholics 
The children who knock at the door for Halloween around here, tend to be quite young and have adults with them. Invariably if I buy sweets, no one knocks, and if I forget, then they do. I don't think there will be too many out tomorrow, cold and wet I gather.