Australia NSW Property and Address Import
NSW does not have a lot of address information in OSM. There is a proposal to use the LPI Access Web Services which we have permission for (and often graphically use as a base layer in JOSM to verify addresses) to add nodes with two tags: "addr:street" and "addr:housenumber". The proposal is detailed in this thread on the imports mailing list.
Data will be posted on the imports and talk-au mailing list for review before uploading to OSM. Suggest to do on a suburb by suburb / postcode by postcode basis. A list of suburbs can be found on the NSW Geographical Names Board by searching for "Designation = Suburb". Given that there are more than 1600 suburbs, this import might take a while. The boundary of the suburb can be found in the LPI Base Map.
As a suburb is reviewed and imported, add it to the git repository and that way we won't double up on work. There is a "review" subdirectory in the git repository where you can post ".osm" files for review. The naming scheme is "SUBURB.osm".