I know I am being paranoid here, but I have always paid my VOA in US dollars.
Can someone please re-assure me that you can pay the VOA in Aussie dollars as well

Yes you can pay in Aussi dollars. Its a quick way to get change when you first arrive

We paid in Aussie dollars and got enough change to pay for the taxi to Legian.
Just make sure when you have paid for your visa it actually states 30 days... there has been a scam lately whereas they have issued a 7 day visa (and paid for 30) people have been forced to pay a fine of hundreds of dollars... for over staying 7 days.
Also, make sure you receive the other half of your immigration form (the one that you fill out on the plane) they keep half and staple the other half in your passport... sometimes they fail to do this you have to pay a 'fine' if you have lost it.
If this happens to you or you do loose the other half... don't panic as there are immigration forms around the departure lounge at the airport.
Hope this helps any newbies to Bali.
Cheers Geri