We've been boo-ed!
This would be a fun activity to start with your Activity Day girls or the young women or young men! For an activity - simply take a plate a goodies to a few houses, with this fun sign w/instructions. Then watch it progress through the ward/neighborhood.
If you've never seen it before - you basically get a plate of goodies anonymously left at your door (or you are the one who starts it by leaving a plate of goodies on a neighbor's porch). You hang up this sign letting others know you've already received one. You then take a plate of goodies to another neighbor (along with a sign for them). Then it continues until all the houses in your neighborhood have been "boo-ed".
You can get this cute BOO sign HERE.