Hello!
My idea is that each housing block has at least one bulletin board each. This way neighbors could leave notes welcoming and introducing each other! It would also be a really great way to organize parties, get togethers, and whatever else people want to do. Bulletin boards would be an awesome way to help increase the social aspect of the game, since it's really easy to keep missing your neighbors. This would definitely make all the blocks have more of an actual "neighborhood" feel.