Last year I came across a website that had everything (but the candy) that we needed to "Boo" our neighbors. The idea is to get everyone in the Halloween spirit. You make up a gift bag of treats, or whatever, attach a note that says "you've been Boo'd", and deliver it anonymously to whoever you want to "Boo." They must then put a note on their door that says "I've been Boo'd." Last year was the first time I had heard of this tradition, but we had fun with it and wanted to do more 'Booing' this year.
Target had cute bags and baskets already made up with the "you've been Boo'd" phrase on them, so others must be getting into the spirit as well. Boogie wanted to "Boo" his friends in the cul de sac, but he also wanted to "Boo" his cousins in North Carolina and some friends of ours in Michigan. Since mailing something would require a return address, we instead decided to send a goody basket and a halloween flower arrangement (for the Mommy's) from a flower service with a simple note that read, "You've been Boo'd." Why should the kids get to have all the fun?