Here are the details from UIP Australia about screenings of Serenity to be followed by a Q&A with Joss Whedon, in both Sydney and Melbourne.

Note that if they aren’t already sold out they will be soon – ring up the cinema directly rather than checking online for the last few tickets.
 

Melbourne:
Tuesday September 13
Village Century City Walk, 285-287 Springvale Road Glen Waverley
Screening starts at 8.30pm, Q&A at 10.30pm
Tickets: $30 each
www.villagecinemas.com.au