Just a thought - once you've got enough neighbors in your 'hood, why not consider:

A. A Street party with a theme?

B. Getting together to build a local bar and/or meeting and greeting place - Baths for Romans - a training field for Celtic warriors - a Tea House in the Orient - etc.?

In other words, get to know your neighbors! A chat is always a possibility as well ;)

The sky's the limit for creativity here.