This was a snippet of my presentation at Sydney GeoRabble explaining what my team did at the 2012 GovHack event. It is only two slides, but covers some of the GIS trickery we needed to do as part of the analysis for the event. Slides are with limited context, unfortunately, as I presented most of the information.

1. Task 1: Simplify LGA Boundaries
ogr2ogr -sql "select g.gid, lga_code11, lga_name11, ste_code11,
area_sqkm, ST_Simplify(g.geom, 0.005) as geom from
lga_2011_aust_2 g order by ST_Area(g.geom) desc" -f kml out.kml
PG:"host=localhost user=postgres dbname=postgis20 password=X"

2. Task 2: Compare touching LGAs
SELECT s1.lga_name11, s2.lga_name11
FROM lga_2011_aust s1, lga_2011_aust_2 s2
WHERE ST_Overlaps(s1.geom, s2.geom);