MapOSMatic. Clever service built on top of OpenStreetMap, which renders double sided city maps with a map and grid on one size and an A-Z street name index on the other. Runs on top of Mapnik, PostGIS and Cairo, with a few thousand additional lines of Python and Django.

Installing GeoDjango Dependencies with Homebrew. brew update && brew install postgis && brew install gdal

Install Django, GeoDjango, PostgreSQL and PostGIS on OSX Leopard. This tutorial worked perfectly for me.

Represent. Andrei Scheinkman and Derek Willis describe how they built the NYTimes Represent feature using GeoDjango and PostGIS.