Halloween is nearing, and AskMen has a really neat article about the 5 Things You Didn't Know About Halloween. For example:
2- Halloween trick-or-treating originated from begging
The only real difference between begging and trick-or-treating is in perspective: The former is lowly, the latter is sanctioned. In fact, some U.S. states don’t hide it, calling Halloween “Beggars' Night,” while some groups have campaigned against the practice, labeling it extortion.
Although no documentary evidence exists, trick-or-treating resembles a practice known as "souling," once performed in the British Isles by poor people around November 1. They would go door to door begging for food; in exchange, they would offer to pray for the souls of the dead.