The Australian Bureau of Statistics has a wealth of information available on its website, the vast majority released under a Creative Commons license. Unfortunately though the data is made available in Excel files which makes programmatic access a little painful.
To help get around this I've created a very simple service that converts time series data from the ABS into XML. It is deployed on AppEngine as absxml.
It's still in its early days - if you have a look on the Issues part of the Project page you'll see some of the things that are yet to be done. However I'm hopeful that it will prove to be a useful stop-gap tool until the ABS starts releasing its data as XML.
absxml is open source, using the very open MIT license (read: do whatever you want) and the full source is available from the project page.