This is a fun activity popular around here for about the past 10 years. I was wondering how prevalent it is throughout the country. This is how it works: You secretly and anonymously (after dark!) leave a "boo" on 2 neighbors' porches. What is a "boo"? It consists of 3 things: (1) a small bag or basket of Halloween candy, stickers, pencils, etc., geared toward the age of the recipient. (2) a boo sign (can be simply a piece of printer paper with a ghost drawn on it and the word BOO in big letters). If you or your kids want to color it, go ahead and be more creative; (3) instructions to the person being boo'ed saying "You've been BOO'ed!" Advise them to enjoy their treats, hang the boo sign they've just received on their door, make 2 photcopies of the boo sign and the instruction sheet, and deliver it along with some treats to 2 neighbors within 24 hours; The idea is that the 2 people you "boo" will "boo" 2 more people and so on and so on. It's fun to see how far it spreads during the time leading up to Halloween. You know who to boo and who's already been boo'ed because they'll have their boo sign taped on their front door. My kids have had so much fun surprising their friends this way. Since it's done anonymously, they have fun keeping their friends guessing as to who boo'ed whom! We have fun going by the houses we boo'ed, and seeing the treat bag gone and the boo sign on their door. Really gets everyone in the Halloween spirit!