I’ve created an open source Yii-powered application called MapApp which shows you how to download and import Zillow.com’s creative commons neighborhood boundary data for the United States and then search and display neighborhood maps with Google Maps. The applet uses Yii, egMap, eGeocoder and MySQL spatial.
Please check it out:
http://jeffreifman.com/2013/08/06/how-to-use-zillow-neighborhood-maps-and-html5-geolocation/
It’s basically excerpted code from my community startup project Geogram … which provides email groups for neighborhoods, neighborhood blocks & apartment buildings and businesses such as coffeeshops, yoga studios, schools, et al.