Over the past year the Portola Planet has been using a great website which brings a new angle tying our real life communities with the community of the online, digital type. Nextdoor.com is a simple website. You sign up, tell it where you live and then post information that would be useful for other neighbors.
One thing the Planet found was that only until the last month or so, really useful information was being shared. This is likely that the amount of people using the site has now reached a point where a real sense of community has been formed and people are talking, and sharing.
So the Portola would highly recommend you head on over and sign up. Of course, the best way to know your neighbors is to get off the computer and get out to the many events in the Portola. But websites like this can be very useful to hear about things happening directly on your street.