After living here five months, I am increasingly less conscious of the Aussie accent(s). That is, I don't really think about the fact that other people sound different until either (a) someone comments on my accent or (b) an Aussie utters a word or phrase that requires some translation (e.g., "we always try to find the daggiest bar at the conference"). In fact, this past weekend I started watching season 1 of "Lost" on DVD, and was immediately struck by all the American accents of the actors, and how familiar Claire, the only Australian who survived the flight from Sydney (!), sounded. As an American, I find that I have to repeat myself quite a bit to others who aren't expecting to hear my accent, as if the other person has to stop and put on their American listening ears. Given that I'm a pretty fast talker, I have also learned to slow down my speech a tad and to enunciate a bit more. I still find some Aussies difficult to understand, and I'm not sure whether it's because of a particular accent or that they're just mumbling. It seems to me that there is quite a range of Aussie accents, but apparently there are 'officially' just three: broad (like Steve Irwin or Crocodile Dundee), general (like Nicole Kidman or a news reader), and cultivated (a nearly extinct accent, closer to British English), which supposedly reflect a rural versus urban background, rather than regional or class differences. A quick search on the web revealed several sites that will teach you how to speak with an Australian accent, such as this one. I particularly like the last tip:
"Keep your tone light and jovial. When speaking with an Australian accent, you should convey happy enthusiasm."
As opposed to that depressing Midwestern American one I have?!