The NSW-government supported HHT organises exhibitions and events in its many historic properties, which include the Rose Seidler house.
This much-improved site focusses on 20th Century deco and modern buildings around Sydney. Lots of photos and links and a series of walks.
Site with an interest in buildings of the period, and a well-stocked links page. Unfortunately it is let down by the bombardment of pop-up ads that the webhost has decided to annoy people with.