The Map Kibera project is an awesome example of community-powered mapping succeeding in a situation where commercial mapping providers would never venture: Kibera, the largest slum of Nairobi, Kenya with a population estimated at near a million. The project will train local residents to create community maps - using OpenStreetMap tools and techniques - and encourage the use of community-generated maps in relief and development efforts.
The article discusses the difficulties in other countries of collectiong geodata or making cartographic development while noting Philippine Association for Inter-Cultural Development (PAFID) activities.
This interesting discusses the community and local uses for 3D modeling and elevation relief models. The article contains a section below for easy reference of what different apspects can benefit from P3DM.
Once we get down to the level of neighborhoods, below the township scale, finding GIS data can be very tricky. Neighborhoods usually aren't officially recognized, at least not by any body large enough or interested enough in creating accurate GIS data descriptions beyond "the houses between East Smith Street and the river."
Online real estate firm Zillow has created this collection of 7000 neighborhood shapefiles and associated geodata. They're under a CC BY SA license so you can use them on anything as long as you credit Zillow and share them along.