Install PostGIS 2.0

install_postgis.md

Install postgresql and postgis

brew install postgresql postgis

Create a GIS-enabled db

psql -d {db} -c "CREATE EXTENSION postgis;"
psql -d {db} -c "CREATE EXTENSION postgis_topology;"

If this fails, check postgis extensions are available with

SELECT * FROM pg_available_extensions;

To see PostGIS version

SELECT PostGIS_full_version();