maps.bigtincan.com service ceased to exist and is no longer useful.
maps.bigtincan.com  is a very useful resource for Australian mappers provided by John Smith. The main website supports the ability to easily load potlatch/getright from the same map by a simple click of the button.
On the postcode  page one can see all the postcode relations defined in Australia.
If you click on a link on this page and you have JOSM running with the remote control plugin installed then JOSM will automatically download the area which contains the selected postcode relation.
Franc has converted postcode boundaries from shape files to OSM files which you can load into JOSM for review/upload
Unnamed roads in a bounding box
This link http://map-data.bigtincan.com/noname-highways.php?left=150&right=151&top=-26&bottom=-27 will download the first 100 unnamed roads in the bounding box with top left corner located at [-26,150] and bottom right at [-27,151].
If you click on a link on this page and you have JOSM running with the remote control plugin installed then JOSM will automatically download the area which contains the unnamed road and highlight it for you.
Unlike the regular tagwatch, this tag watch copes with nodes and relations, not just ways. It's also updated much more frequently and you can even force it to reload individual nodes, ways or relations without waiting for the automatic process to kick in.
Each Sunday after lunch the system automatically generates a navit binary file, you can download it from here: http://map-data.bigtincan.com/data/
BTC Mapper is a live POI uploader currently available for Black Berry and Android platforms, that lets you send information on the spot directly to the OSM DB, primarily points of interest.