The Aussie accent is enough to stymie many voice recognition packages. Open source project VoxForge is hoping to overcome that (and many of the other problems associated with trying to build a voice recognition system) by asking users to contribute voice samples for use in speech recognition projects.
Commercial software developers often purchase large collections of voice recordings (often referred to as a corpus), but open source projects can't usually do that, because they don't have the money and the licensing conditions for the corpus often clash with the licences used for the projects.
Contributing to VoxForge is easy; you can do so straight from the site using a Java applet, which guides you through reading through a series of ten sentences. Once you're done, you simply upload them from the site. It's a helpful thing to do if you've got some spare time, even if the sentences are pretty esoteric.